There are 2 main definitions of base in English:


Line breaks: base
Pronunciation: /beɪs


1The lowest part or edge of something, especially the part on which it rests or is supported: she sat down at the base of a tree
More example sentences
  • Resting at the thick base of the old tree sat a beautifully etched envelope.
  • Her other arm held a shield by her side, the base rested on the floor but she was not leaning on it.
  • Because the base of the stone barely touches the base upon which it rests, it appears that it could easily fall over when the sea wind blows.
1.1 Architecture The part of a column between the shaft and pedestal or pavement.
More example sentences
  • Axial loading from earthquakes is minimized by seismic dampers under the column bases.
  • Column bases, doorsteps, baseboards, and beams - even the interior roof tiles and gutters - all are decorated.
  • To prevent vandalism and damage, the bases of columns are clad in stainless steel.
1.2 Botany & Zoology The end at which a part or organ is attached to the trunk or main part: a shoot is produced at the base of the stem
More example sentences
  • Their long, whip-like tail has a small dorsal fin near its base and up to five venomous spines.
  • River otters have paired scent glands at the base of their tail which give off a heavy, musky smell.
  • The petiole or stipe is the stalk at the base of the frond, before the first pinna ‘branches’ from the rachis.
1.3 Geometry A line or surface on which a figure is regarded as standing: the base of the triangle
More example sentences
  • The two points of intersection of the latter with the sides of the triangle lie on a line parallel to the base.
  • If the height of a rectangle is 7 1/6 mm and the perimeter is 27 2/15 mm, what is the length of the base of the rectangle?
  • The length of the base of the rhombus is the length of one of its sides, here shown with 'b'.
1.4 Surveying A known line used as a geometrical base for trigonometry.
More example sentences
  • All of the angles and at least one side (the base) of the triangulation system are measured.
  • The base triangulation should have boundary faces; a completion is simply a new triangulation formed from the base triangulation by gluing all of the boundary faces to each other in some fashion
  • After that, a base triangulation is performed.
1.5 Heraldry The lowest part of a shield.
More example sentences
  • Attached on either side of the base of the shield is a doubled, stacked scroll with the upper portion the same angle as the shield.
  • On the purple segment at the base of the shield is a silver stag, trotting with one fore hoof raised, within a silver ring.
  • The eagle with the outstretched wings at the base of the shield stands for loyalty to country; the olive branch in the right claw being emblematic of out national dedication to the cause of peace, while the arrows in the left claw indicate our readiness to fight for justice and freedom.
2A conceptual structure or entity on which something draws or depends: the town’s economic base collapsed
More example sentences
  • This is the key point of the book, but I am less convinced of this claim and not quite sure what lessons might be drawn from it for understanding the broader bases for sustained economic growth.
  • Felsenstein et al. 1999 compare the conceptual bases of these approaches.
  • And so there are three bases for friendships, depending on which of these qualities binds friends together.
2.1A foundation or starting point for further work: she uses existing data as the base for the study
More example sentences
  • That which was, is the foundation for what is now, which becomes the base for what is to come.
  • It started with the Native Americans who set the base for all the development.
  • It also provides a new base for vital research and study of the disease carried out by the University of Sheffield.
basis, bedrock, foundation, core, essence, essential, nitty-gritty, basics, starting point, key component, fundamental, root(s), heart, backbone, theory, principle, rationale;
source, origin, spring, well head, fountainhead, fount
2.2 [with modifier] A group of people regarded as supporting an organization, for example by buying its products: a customer base
More example sentences
  • There is likely to be an existing customer base for the new product and therefore the risks are lower.
  • A deal would allow them to merge the private client customer bases of two of the second tier stockbrokers in the Irish market.
  • Ten years ago the company had a customer base of only 45000 clients, with 2450 employees.
3A place used as a centre of operations by the armed forces or others; a headquarters: he headed back to base
More example sentences
  • Living on a Marine base on the edge of restive Ramadi is a shock to a civilian's senses.
  • Analysts have criticised Karzai for clumsy attempts to impose his will by sending in appointees to try to implement disarmament without necessary support bases, or central backup.
  • He stressed the successes not just of the aircrew but of the hundreds of Combat Support Group personnel supporting combatant forces at bases within and outside Australia.
headquarters, centre, starting point, camp, site, station, settlement, post
3.1The main place where a person works or stays: she makes the studio her base your hotel is a good base from which to explore
More example sentences
  • Peter's first six months will be very much a getting to know you process and will involve some travel, but Stephen Street will be his firm base.
  • He continues to shuttle between Chennai, his base for over a decade now, and Kerala where he has several teaching assignments.
  • We then proceeded to our hotel which is the Catic Plaza, which was to become our base for five nights and it was the essence of luxury in every way.
4A main or important element or ingredient to which other things are added: soaps with a vegetable oil base
More example sentences
  • There is a firm called Kuze, based in Ikebukuro, Tokyo, specializing in sauces and soup bases.
  • Syrups are made with a base of sugar syrup, honey or perhaps maple syrup.
  • It has the Dr Pepper flavors as a base with berries thrown into the mix.
medium, vehicle, carrier
4.1 [mass noun] A substance into which a pigment is mixed to form paint, such as water, oil, or powdered aluminium hydroxide.
More example sentences
  • Whether you choose water or solvent base, your next choice is going to be liquid or semi-paste.
  • Using oil base paint or glaze will slow the drying time and allow you more time to blend your veins.
  • The alcohol and dissolved base are then mixed with the oil and agitated for one to two hours.
4.2 [mass noun] A substance used as a foundation for make-up: her make-up artist works with base, eye make-up, and lipstick
More example sentences
  • Makeup base is one of the most commonly misused cosmetics, but it doesn't have to be.
  • To make eye colours ‘pop,’ use a light or neutral concealer as your eye makeup base.
  • You can reshape your brows this way: Cover the brows with an opaque makeup base.
5 Chemistry A substance capable of reacting with an acid to form a salt and water, or (more broadly) of accepting or neutralizing hydrogen ions. Compare with acid and alkali.
More example sentences
  • Nitric acid reacted with a base will give the nitrate of the salt and water.
  • Neutralization is a chemical reaction in which a base reacts with an acid to create water and a salt.
  • They found that these nonaqueous-superacid solutions reacted with weak bases which did not react with either sulfuric or perchloric acid in water.
5.1 Biochemistry A purine or pyrimidine group in a nucleotide or nucleic acid.
More example sentences
  • Purine salvage pathway allows interconversion of bases, nucleosides and nucleotides.
  • There are four DNA bases: adenine, cytosine, guanine, and thymine (A, C, G, and T).
  • The nucleosides are better models for the bases in DNA and RNA because the sugar moiety eliminates tautomers that cannot occur in the polymers.
6 Electronics The middle part of a bipolar transistor, separating the emitter from the collector.
More example sentences
  • Transistors are composed of three parts - a base, a collector, and an emitter.
  • The presence of this P + layer results in pinch-off between itself and the bipolar base.
  • A resistor RB is required to limit the current flowing into the base of the transistor and prevent it being damaged.
7 Linguistics The root or stem of a word or a derivative.
More example sentences
  • The children had to say the base of a suffixed word pronounced by the experimenter.
  • According to Crystal, a prefixation is “an affix is placed before the base of the word” (1997, p. 90).
  • The Greek Xu-w, which etymologists justly connect with our loose, loosen, may possibly be the base of the word.
7.1The uninflected form of a verb.
More example sentences
  • So if you want to conjugate a regular - er verb, simply remove the - er ending from the infinitive and place the base of the verb in front of the endings.
  • Determine the ending of the verb that goes with that pronoun and add it to the base of the verb you want to use in the sentence.
  • The verb base is what you look up in the dictionary when you want to know how to say something.
8 Mathematics A number used as the basis of a numeration scale.
More example sentences
  • Some historians believe that the Babylonian base 60 place-value system was transmitted to the Indians via the Greeks.
  • The Egyptians had a bases 10 system of hieroglyphs for numerals.
  • There is no logical reason why we cannot use any integer bigger than zero for a base.
8.1A number in terms of which other numbers are expressed as logarithms.
More example sentences
  • In that year Briggs gave a numerical approximation to the base 10 logarithm of e but did not mention e itself in his work.
  • Choosing different numbers gives logarithms to different bases.
  • Taking logarithms to the base, we are looking for a solution.
9 Baseball Each of the four stations that must be reached in turn to score a run.
More example sentences
  • Four different times I switched over to see the bases loaded, scoring I believe a total of one run.
  • He first arranged four of these in a diamond-shaped pattern to represent the bases and home plate.
  • There's no reason he shouldn't hit 30 home runs and steal 30 bases if he stays healthy.


[with object] Back to top  
1 (base something on) Use (something specified) as the foundation or starting point for something: the film is based on a novel by Pat Conroy entitlement will be based on income
More example sentences
  • This defines the foundation our society is based on: equal rights, freedom and peace.
  • Miramax has hired playwright Warren Leight to come up with a script, but Roddy Doyle - who wrote the novel the original film was based on - will not be getting involved.
  • Although he based his films on Kannada novels, the novelists complained that their stories had been altered.
found, build, construct, form, establish, ground, root;
use as a basis;
rest, hinge;
emanate from, derive from, spring from, stem from, originate in, have its origin in, can be traced back to
2Situate at a specified place as the centre of operations: the Science Policy Review Unit is based at the University of Sussex (as adjective, in combination -based) a London-based band
More example sentences
  • All operations are home based and will require just a couple of hours of your time.
  • In recent weeks, the flights have been stopping at Larnaca in Cyprus where BA is basing its crews operating to the Middle East.
  • As a result, both are now basing themselves at the Endurance Performance Centre at St Mary's University, Twickenham.


Middle English: from Old French, from Latin basis 'base, pedestal', from Greek.


get to first base

[usually with negative] informal , chiefly North American Achieve the first step towards one’s objective: he never got to first base in the litigation
More example sentences
  • I'll admit up front that my favorite unorthodox (the word has no religious connotation in this context) Texas contender never got to first base.
  • She says that not only is the family service she runs snowed under, she says the local DOCS office isn't even getting to first base on some allegations.
  • Unfortunately, most bands and artists can't get to first base unless their music fits one of these formats, and there are many other bands and other types of music-like mine-that don't fit into any set genres.

off base

informal Mistaken: the boy is way off base
More example sentences
  • In reflecting on what I wrote yesterday about all the American soldiers being war criminals, I realize that I was way off base.
  • I thought your editing was off base, by the way, as are most of your long-winded comments on this site.
  • I'd say the comparisons to Nazis and Hitler are not only off base, but a blatant attempt to further demonize America and its troops.

touch base

informal Briefly make or renew contact with someone: they are travelling back to Star City, where they plan to touch base with relatives
More example sentences
  • That is calling people, touching base with contacts.
  • If you aren't hunting for new sources of supply, you may use the opportunity to touch base and renew relationships.
  • I finally got sick of wondering what she was up to, and touched base, and we are now in regular, close contact.

Definition of base in:

There are 2 main definitions of base in English:


Line breaks: base
Pronunciation: /beɪs


1Without moral principles; ignoble: the electorate’s baser instincts of greed and selfishness
More example sentences
  • And it is one way to shine moral clarity on a subject that too often inspires only base moral equivalence.
  • My base instinct was to go round the dressing room and clip a few, but unfortunately those days were well gone.
  • By appealing to the base instincts of race and religion the President and his able cohorts are naturally inducing one crisis after the other.
sordid, improper, low, mean, bad, wrong, evil, wicked, iniquitous, immoral, sinful;
unscrupulous, unprincipled, unseemly, unsavoury, shoddy, squalid, vile, foul, vulgar, tawdry, cheap, low-minded, debased, degenerate, depraved, corrupt, reprobate, dissolute, dishonest, dishonourable, disreputable, despicable, discreditable, contemptible, petty, ignominious, ignoble, shameful, wretched, scandalous, infamous, abhorrent, abominable, disgusting
2 archaic Denoting or befitting a person of low social class.
More example sentences
  • The thought of such a man with a background of base peasants to be Kikyo's teacher was almost ludicrous.
  • "Fetch, base peasant!! Remain invisible!!!" demanded your cold visage.
  • Farewell, base peasant, and thank God thy fathers were no gentlemen.
3(Of coins or other articles) not made of precious metal: the basest coins in the purse were made in the 620s ad
More example sentences
  • A longtime goal of the alchemists was the transmutation of base metals into precious metals.
  • Most modern currencies are fiat currency, allowing the coins to be made of base metal.
  • Compared with precious metals, base metals are plentiful in nature and therefore much cheaper, of course.


late Middle English: from Old French bas, from medieval Latin bassus 'short' (found in classical Latin as a cognomen). Early senses included 'low, short' and 'of inferior quality'; from the latter arose a sense 'low in the social scale', and hence (mid 16th century) 'reprehensibly cowardly, selfish, or mean'.



More example sentences
  • Some observers interpret these symbols cynically, as opportunistic, basely commercial, unquestioningly nationalistic expressions of pro-war sentiment.
  • See how men, who have been well-trained, prefer to receive a blow rather than basely avoid it!
  • Can she who professed delicacy of sentiment and sincere regard for me, use me so very basely and so very cruelly?

Definition of base in: