Definition of warn in English:

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Pronunciation: /wɔːn/


[reporting verb]
1Inform someone in advance of a possible danger, problem, or other unpleasant situation: [with object]: his father had warned him of what might happen [with direct speech]: ‘He’s going to humiliate you,’ John warned [no object]: traffic signals warned of fog [with clause]: the union warned that its members were going on strike
More example sentences
  • The report also warned of the dangers of failing to improve the lot of ordinary Iraqis.
  • It was a habit left over from the old days when the king and his ministers were thus warned of danger.
  • Because of the possible dangers we are warning customers not to use them.
notify, alert, apprise, give notice, inform, tell, let someone know, make someone aware, give a warning to, give fair warning to, forewarn, put someone on notice/guard, remind;
raise/sound the alarm
informal tip off, put wise
1.1 [with object] Give someone cautionary advice about their actions or conduct: he warned the chancellor against raising taxes [with object and infinitive]: police warned people not to keep large amounts of cash in their homes [no object]: they warned against false optimism
More example sentences
  • Police are warning drivers to remain cautious today after a winter storm dumped as much as 14 inches of snow on parts of eastern Virginia.
  • Whatever the reason, Shuggy's behaviour eventually prompted a police caution, warning him that if he didn't calm down then he would be in serious trouble.
  • Police are warning the public to be cautious when opening their door to strangers.
advise, exhort, urge, counsel, caution;
put on the alert, put someone on guard


warn someone off the course

Horse Racing Prohibit someone who has broken the laws of the Jockey Club from riding or running horses at meetings under the Jockey Club’s jurisdiction.
Example sentences
  • Was this a chance to warn him off the course?
  • The murkier side of racing continued to make headlines as talented ex-jockey Graham Brown was warned off for eight years after being found guilty by the Jockey Club of bringing the sport into disrepute.
  • Ex-jockey Dermot Little was warned off for a further 20 years while another former rider Graham White was banned for five years.

Phrasal verbs

warn someone off

Order someone to keep away from (somewhere) or refrain from doing (something): he has been warned off booze
More example sentences
  • While many shunned the Ayrshire stockbroker during his period of exile from the tracks - he was warned off for ten years for his part in scandal.
  • Just as he is about to get to the bottom of the affair, he is warned off by the American ambassador in Saigon.
  • Now when John Main began has explorations into meditation he was warned off that path by his own order, was he not?



Example sentences
  • The helicopter's electronic warfare systems include a radar warning receiver, laser warning receiver, missile approach warner and chaff and flare dispensers.
  • The laser warner provides broadband laser frequency coverage to detect and display rangefinding, designating and missile guidance laser threats.
  • The defensive aids suite could include a radar warner, missile launch and approach warner, and chaff and flare decoy dispensers.


Old English war(e)nian, wearnian, from a West Germanic base meaning 'be cautious'; compare with ware2.

Words that rhyme with warn

adorn, born, borne, bourn, Braun, brawn, corn, dawn, drawn, faun, fawn, forborne, forewarn, forlorn, freeborn, lawn, lorn, morn, mourn, newborn, Norn, outworn, pawn, prawn, Quorn, sawn, scorn, Sean, shorn, spawn, suborn, sworn, thorn, thrawn, torn, Vaughan, withdrawn, worn, yawn

For editors and proofreaders

Line breaks: warn

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