Definition of crack in English:

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Pronunciation: /krak/


1A line on the surface of something along which it has split without breaking apart: a hairline crack down the middle of the glass
More example sentences
  • Calmer now, Jack stepped over to the window and drew a line along the crack with his bare finger.
  • It's surface was not impressive; cracks ran along the wall and the paint was slowly being peeled off by the weather.
  • I ran my finger along the cracks in the wall as I walked.
1.1A narrow space between two surfaces which have broken or been moved apart: he climbed into a crack between two rocks the door opened a tiny crack
More example sentences
  • The terrain is easy to move over, hard mud with deep narrow cracks, easy to cross, but wide enough to hide in.
  • The guards opened the slightest crack in the door enough for her to slip through and beckon her closer.
  • As soon as the slightest crack was opened, the being started to move toward it.
1.2A vulnerable point; a flaw: the company spotted a crack in their rival’s defences
More example sentences
  • They saw the flaws and cracks in the system. [But] we have to move on and think beyond one man.
  • He wanted to find a crack, something left vulnerable between the duo.
  • I've had to stop trying to look for cracks and flaws to prove that it's not as good as it seems.
2A sudden sharp or explosive noise: a loud crack of thunder
More example sentences
  • Lightning flashed again outside, followed quickly by a loud crack of thunder.
  • She landed with a loud thud and a crack came from her ankle.
  • He winced when a twig snapped with a loud crack beneath his foot.
bang, report, explosion, detonation, clap, pop, snap, crackle, knock, tap, clash, crash, smash, smack
informal wham, whump
2.1A sharp audible blow: she gave the thief a crack over the head with her rolling pin
More example sentences
  • What Montgomery conceived was a one-two punch, a British blow followed by an American crack.
  • My dad would get the report from our mother, make his way into our room, take off his belt, and deliver the requisite number of cracks.
blow, bang, hit, punch, knock, thump, rap, bump, thwack, smack, slap, welt, cuff, box
informal bash, whack, clobber, clout, clip, wallop, belt, tan, biff, bop, sock, lam, whomp
British informal slosh
North American informal boff, bust, slug, whale
Australian/New Zealand informal dong
dated buffet
2.2A sudden harshness or change in pitch in a person’s voice: the boy’s voice had an uncertain crack in it
More example sentences
  • The bottom lip started going and there was a crack in my voice.
  • He adopts a half-sob crack in the voice with monotonous repetition.
  • Singing in English at the impossibly low volumes she favors, syllables are often lost as her voice shows fine cracks.
3 informal A joke, typically a critical or unkind one: he knew about the gossip and would make the odd crack
More example sentences
  • There were all sorts of cracks and jokes about diving off wardrobes etc.
  • They continued to lazily watch Stine, exchanging cracks and small jokes about the dog.
  • When he explains that the crack about encouraging homemakers to become lawyers was a joke, she chides him about his tone.
joke, witticism, funny remark, witty remark, jest, quip, pun, sally, pleasantry, epigram, aphorism;
repartee, banter;
French bon mot;
jibe, barb, jeer, sneer, taunt, insult, cutting remark, slight, affront, slur, insinuation
informal one-liner, gag, wisecrack, funny, dig
4 (also craic) [mass noun] chiefly Irish Enjoyable social activity; a good time: he loved the crack, the laughing
More example sentences
  • There was good food, good music and plenty chat and craic and a most enjoyable night was had by all.
  • This is a very popular event with plenty of entertainment and craic on the night.
  • The town prides itself in being a festival meeting, with plenty of craic on the streets and in the pubs at night.
4.1 [count noun] Scottish & Northern English A conversation: they are having a great crack about shooting
5 [in singular] informal An attempt to achieve something: I fancy having a crack at winning a fourth title
More example sentences
  • I've had a crack at taking some more pics, some have turned out OK.
  • Our greatest living portraitist, Lucian Freud, had a crack at it in 2001.
  • Two points later he had a crack at a second serve from Federer and took a big swing.
attempt, try, effort, endeavour, venture
informal go, shot, stab, whack, whirl
formal essay
archaic assay
5.1A chance to attack or compete with someone: he wanted to have a crack at the enemy
More example sentences
  • ‘He's dangerous,’ says Bungu, who opted to have a crack at the combative Yorkshireman.
  • then you may as well have a crack at a test, if only for the heck of it.
  • We want to do well in the Trophy and it would be great if we could get through this round and have a crack at one of the Conference clubs.
6 (also crack cocaine) [mass noun] A potent hard crystalline form of cocaine broken into small pieces and inhaled or smoked: he uses crack and cocaine [as modifier]: a crack dealer
More example sentences
  • It will currently include, among many other substances, cannabis, heroin, cocaine, crack, LSD and ecstasy.
  • Pot dealers report that there has been no discernible increase in trafficking of the harder drugs - crack, cocaine, and heroin.
  • This suggested that marijuana use was not a necessary precursor to use of crack, powder cocaine, or heroin.


1Break or cause to break without a complete separation of the parts: [no object]: the ice all over the bog had cracked [with object]: take care not to crack the glass
More example sentences
  • Mark kicked the glass and it cracked, he kicked again breaking it.
  • I put a glass of water outside just to see what would happen; not only did it freeze within minutes, but the glass cracked as well.
  • All that was salvaged from the ruin was a brass barometer with its front glass cracked.
split, fracture, fissure, rupture, break, snap, cleave
rare craze
1.1Break or cause to break open or apart: [no object, with adverbial]: a chunk of the cliff had cracked off in a storm figurative his face cracked into a smile [with object]: she cracked an egg into the frying pan
More example sentences
  • Its superstructure began to fissure and crack apart from the concentrated barrages.
  • One of the claws broke in the attempt to lift the submarine, and a large section of its hull cracked off and fell back to the ocean floor.
  • It was as if someone had cracked open an egg on the top of my head.
1.2 [with object] Break (wheat or corn) into coarse pieces.
Example sentences
  • If you don't have access to a grinder to crack wheat for cereal, you can cook the wheat kernels.
  • They can churn butter, crack corn and feed it to the chickens, and tend the garden.
  • There is also a kit for a processor that can crack corn and remove seeds from cotton with simple attachments.
1.3Give way or cause to give way under torture, pressure, or strain: [no object]: the witnesses cracked and the truth came out [with object]: no one can crack them—they believe their cover story
More example sentences
  • Clearances were being returned instantly and, under relentless pressure, their defence cracked.
  • A decorated Gulf War veteran, he was moulded into a killing machine, but cracked under the pressure of war.
  • After his early promise first shown at the Monte Carlo Masters, he cracked under pressure.
break down, give way, cave in, crumble, collapse, go to pieces, lose control, yield, succumb, founder
informal fall/come apart at the seams
2Make or cause to make a sudden sharp or explosive sound: [no object]: a shot cracked across the ridge [with object]: he cracked his whip and galloped away
More example sentences
  • She stretches, her stiff joints snapping and cracking loudly, sounding just like a firecracker when lit.
  • The shot rang out, cracking loudly and landing in an unknown spot.
  • He heard the ice cracking, the sound traveling up through the soles of his feet.
go bang, bang, pop, snap, crackle, crash, thud, thump, boom, ring out, clap;
explode, detonate
2.1 [no object] Knock hard against something: she winced as her knees cracked against metal
More example sentences
  • She found herself falling hard, the floor cracking against her ribs and back.
  • His toe cracked against something hard and out of place.
  • Song's head cracked hard on the floor next to the welcome mat.
2.2 [with object] Hit (someone or something) hard: she cracked him across the forehead
More example sentences
  • I realised he wasn't breathing, so I turned him over face down across my arm and cracked him really hard on his back a couple of times.
  • They want to see the police ‘go in hard and crack some heads on the terraces’.
  • While I bent down the door swung to and cracked me hard on the forehead.
hit, strike, beat, thump, hammer, knock, rap, pound, thud, punch, bump, thwack, smack, slap, slam, welt, cuff, pummel, buffet, box someone's ears
informal bash, whack, clobber, clout, clip, wallop, belt, tan, biff, bop, sock, lam, whomp
British informal slosh
North American informal boff, bust, slug, whale
Australian/New Zealand informal dong
2.3 [no object] (Of a person’s voice) suddenly change in pitch, especially through strain: ‘I want to get away,’ she said, her voice cracking
More example sentences
  • I yelled, my voice cracking and squeaking through my panic.
  • The story takes Pat Williams back almost 23 years, and even now, his voice cracks and quivers over the telephone as he tells it.
  • ‘Um yeah I'll be out in a minute,’ Cassie quickly answered hearing her voice crack.
3 [with object] informal Find a solution to; decipher or interpret: the code will help you crack the messages
More example sentences
  • Otherwise, you're making it much easier for someone to crack your code.
  • This might be a hard fact to crack, but you're growing up - and fast!
  • The lyrical logic is hard to crack, but the record proves maddeningly infectious.
solve, find an/the answer to, find a/the solution to, resolve, work out, puzzle out, fathom, find the key to, decipher, decode, break, clear up, interpret, translate, straighten out, get to the bottom of, make head or tail of, unravel, disentangle, untangle, unfold, piece together, elucidate
informal figure out, suss out
3.1Break into (a safe).
Example sentences
  • A tourist attraction will invite visitors to race a motorised gondola, crack a safe and save the world by defusing a bomb.
  • And, if he had to worry about beating the box, would he be able to crack the safe without zoning out?
  • She cracks safes as well as her father.
4 [with object] Tell (a joke): he cracked jokes which she didn’t find very funny
More example sentences
  • Hang on, weren't we cracking the same joke last year?
  • He cracked a few jokes as he became comfortable with the podium.
  • I'm just about to crack a rather forced joke to her when something over her shoulder catches my eye.
5 [with object] Decompose (hydrocarbons) by heat and pressure with or without a catalyst to produce lighter hydrocarbons, especially in oil refining: catalytic cracking increases gasoline yields
More example sentences
  • Palladium catalysts are used in refining and cracking petroleum.
  • Methanol and ethanol are most commonly derived from cracking petroleum into smaller hydrocarbons.
  • Amorphous alumina-silica composites are used to crack or split hydrocarbon chains in petroleum refining.


Very good or skilful: he is a crack shot crack troops
More example sentences
  • But the Marines are different; they are crack troops, as trained physically as we are intellectually.
  • A superb siege by sea was planned and he was given six thousand of the best Syrian crack troops to accomplish the feat.
  • Mounted on horseback, a small team of crack troops are aware that locals know they are coming well in advance.



crack a book

North American informal Open a book and read it; study: they can run with a football or dunk a basketball with little concern whether they ever crack a book
More example sentences
  • Try cracking a book occasionally or move to a country where they make special accommodation for ignorant protesters such as yourself.
  • Relax in a hammock, crack a book under a tree, drink iced tea on the front porch.
  • There are cheat codes to the universe, as anyone who's cracked a book on differential calculus can tell you.

crack (open) a bottle

Open a bottle, especially of wine, and drink from it: he likes to crack a bottle of wine with his friends
More example sentences
  • At least the achievements gave middle England an excuse to stay up late and crack a bottle of Chardonnay.
  • There is always something to celebrate, always a reason to crack a bottle.
  • She cracked a bottle of beer and poured it over.

crack a crib

archaic, informal Break into a house.
Example sentences
  • He'll crack a crib in Scotland one week, and be raising money to build an orphanage in Cornwall the next.
  • He give me a fiver once after cracking a crib.

crack hardy

Australian /NZ informal Assume a brave or tough front in the face of a difficult or unpleasant situation: we cracked hardy but we were in shock
More example sentences
  • We saw him try to crack hardy with a little laugh, the false laughter that comes from a heart that only wants to scream and rage against the world.
  • We can take his tweet that he is "over the moon at the prospect of the contest" as a touch of cracking hardy.
  • He was nearly crying as he cracked hardy.

crack of dawn

A time very early in the morning; daybreak: I’ve been up since the crack of dawn
More example sentences
  • In fact, I was at a sunrise service at the crack of dawn earlier today, service for Easter Sunday.
  • I would wake up early in the morning at the crack of dawn, go to Shivaji Park and watch the children play for hours.
  • We started our journey, at the crack of dawn, as the early morning sun shone behind the morning mist.

crack of doom

A peal of thunder announcing the Day of Judgement: I fell off the ladder, making a noise like the crack of doom
More example sentences
  • His comments regarding America ‘till the crack of doom,’ told the world exactly where they stood.
  • Hammond remarked that ‘He comes off the pitch like the crack of doom.’
  • Thus was Hollywood given the maniacal sense of its own importance that will continue to inflate until the crack of doom.

crack of the whip

British informal A chance to try or participate in something: individuals who feel that they have not had a fair crack of the whip
More example sentences
  • I want to give myself a fair hearing and as long as I get a fair crack of the whip, that's all I can hope for.
  • My concern is that there is a pot of money at the National Assembly and the south is getting a fair crack of the whip.
  • Men are not getting a fair crack of the whip, and I'm prepared to say so in court.

be cracked up to be

[with negative] informal Be asserted to be (used to indicate that someone or something has been described too favourably): life on tour is not as glamorous as it’s cracked up to be
More example sentences
  • As far as U.K. saviours go, the band aren't what they'll surely be cracked up to be.
  • Life as a Telephone Sales Representative, surprisingly, is not all it may be cracked up to be.
  • Religious services and ceremonies never strike Miss Manners as being as funny as they may be cracked up to be.

crack wise

North American informal Make jokes: this struck them as funny, although nobody used it as a moment to crack wise at my expense
More example sentences
  • But the freedom to live involved more than cracking wise.
  • The international news is so unrelentingly grim I don't feel like cracking wise about the situation.
  • He cracks wise but can't hide the grimace each taste brings.

get cracking

informal Act quickly and decisively: most tickets have been snapped up, so get cracking if you want one
More example sentences
  • I got bored very quickly and slipped off to the study to get cracking on the current chapter of the book.
  • If you can, then I expect you to get cracking on an Internet decision soon so you can reap the rewards!
  • This building used to be a power station and was where Hitchcock got cracking on his early stuff.

slip (or fall) through the cracks

another way of saying slip through the net (see net1).

Phrasal verbs


crack down on

informal Take severe measures against: the police will crack down on criminals
More example sentences
  • Sydney police have promised to crack down on all such surreptitious snapping.
  • Labour has taken tough measures to crack down on crime and anti-social behaviour.
  • The Executive has introduced measures through the police bill to crack down on knife culture.
get tough on, take severe/stern measures against, clamp down on, come down heavily on;
eliminate, abolish, eradicate, extinguish, quench, repress, stifle, suppress, put an end to, put a stop to, end, finish, get rid of, crush, put down, weed out, curb, nip in the bud, thwart, frustrate, scotch, squash, quash, quell, subdue, terminate, beat, overcome, defeat, rout, destroy, demolish, annihilate, wipe out, extirpate;
limit, restrain, restrict, check, keep in check, control, keep under control
informal come down on like a ton of bricks, squelch, put the kibosh on, clobber

crack on

British informal Proceed or progress quickly: we’ll crack on with the rest of the job this month
More example sentences
  • You have to put it to one side and crack on with it.
  • I can crack on with training now and try and get back in the first team.
  • Our attitude now is just to crack on with it and move on.

crack on to

Australian informal Seek to form a sexual relationship with (someone).
Example sentences
  • The little tramps probably crack on to 31-year-olds all the time at their local suburban blue light disco.
  • Between Paula having hysterics and Brad cracking on to Bessie - well, everything was a-buzz as you can imagine.
  • And it's true… if I had a boyfriend; he probably would have a problem with another guy cracking on to me.

crack up

1 informal Suffer an emotional breakdown under pressure: I feel I’m cracking up, always on the verge of tears
More example sentences
  • I was short-tempered and I was cracking up a bit under the pressure of it all.
  • ‘If I had not had Diana and the children I would have cracked up and had a mental breakdown by now,’ he said.
  • His stylish arthouse flick looks at three women as they crack up.
break down, have a breakdown, lose control, be overcome, collapse, go to pieces, go out of one's mind, go mad, crumble, disintegrate
informal lose it, lose one's cool, fall/come apart at the seams, go crazy, freak out
2 informal Burst into laughter: she tries to keep a straight face, but she keeps cracking up
More example sentences
  • He cracks up into laughter, his shoulders heaving uncontrollably.
  • I really cracked up in laughter when I read the headline ‘Protest is the backbone of democracy’.
  • Before I knew it I was buzzed and cracking up with laughter.
burst out laughing, dissolve into laughter, roar with laughter, shake with laughter, laugh uncontrollably, guffaw, be doubled up, split one's sides, hold one's sides
informal fall about, be in stitches, break up, crease up, be creased up, be rolling in the aisles, laugh like a drain


Old English cracian 'make an explosive noise'; of Germanic origin; related to Dutch kraken and German krachen. sense 4 of the noun is from Irish craic 'entertaining conversation'.

  • In Old English crack meant ‘make a sudden sharp or explosive noise’. The drug known as crack, or crack cocaine, is a hard crystalline form of cocaine broken into small pieces and smoked. It gets its name from the ‘cracking’ noises the crystals make as they are heated. The ‘crack’ or lively socializing in a pub is an Irish use, first recorded in the 1920s and sometimes written craic, that comes from the Scottish sense ‘chat, conversation’. You can talk about a time very early in the morning as the crack of dawn. The expression is first recorded in the late 19th century, in the form crack of day. The crack here is the crack of a whip, with an additional echo perhaps of break of day and daybreak, and the notion of the sky cracking or breaking open to reveal a sliver of light. The crack of doom is a peal of thunder which, according to the Book of Revelation, will announce the Day of Judgement. See also paper, pop

Words that rhyme with crack

aback, alack, attack, back, black, brack, clack, claque, Dirac, drack, flack, flak, hack, jack, Kazakh, knack, lack, lakh, mac, mach, Nagorno-Karabakh, pack, pitchblack, plaque, quack, rack, sac, sack, shack, shellac, slack, smack, snack, stack, tach, tack, thwack, track, vac, wack, whack, wrack, yak, Zack

For editors and proofreaders

Line breaks: crack

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