- to give notice, advice, or intimation to (a person, group, etc.) of danger, impending evil, possible harm, or anything else unfavorable: They warned him of a plot against him. She was warned that her life was in danger.
- to urge or advise to be careful; caution: to warn a careless driver.
- to admonish or exhort, as to action or conduct: She warned her employees to be on time.
- to notify, advise, or inform: to warn a person of an intended visit.
- to give notice to (a person, group, etc.) to go, keep at a distance, etc. (often followed by away, off, etc.): A sign warns trespassers off the grounds. A marker warned boats away from the dock.
- to give authoritative or formal notice to (someone); order; summon: to warn a person to appear in court.
- to give a warning; caution: to warn of further disasters.
Origin of warn
- to notify or make (someone) aware of danger, harm, etc
- (tr; often takes a negative and an infinitive) to advise or admonish (someone) as to action, conduct, etcI warn you not to do that again
- (takes a clause as object or an infinitive) to inform (someone) in advancehe warned them that he would arrive late
- (tr; usually foll by away, off, etc) to give notice to go away, be off, etche warned the trespassers off his ground
Word Origin and History for pre-warning
Old English warnian "to give notice of impending danger," also intransitive, "to take heed," from West Germanic *warnojanan (cf. Old Norse varna "to admonish," Old High German warnon "to take heed," German warnen "to warn"); related to Old English wær "aware, cautious" (see wary). Related: Warned; warning.