the act or utterance of one who warns or the existence, appearance, sound, etc., of a thing that warns.

something that serves to warn, give notice, or caution

We fired a warning at the intruders.

Meteorology . an announcement from the U.S. National Weather Service alerting the public that a storm or other weather-related hazard is imminent and that immediate steps should be taken to protect lives and property. Compare advisory ( def. 5 ) , storm warning ( def. 2 ) , watch ( def. 20 ) .

serving to warn, advise, caution

a warning bell.

adjective

admonishing , admonitory , cautioning , exemplary , exhortatory , monitorial , monitory , ominous , premonitory , threatening , admonitorial , deterrent , exhortative , homiletic , mentorial , pathognomonic , prodromal , salutary , sematic

noun

admonition , advice , alarm , alert , augury , caution , caveat , distress signal , example , exhortation , fore , foretoken , forewarning , guidance , handwriting on wall , heads up , hint , indication , information , injunction , intimation , lesson , look out * , mayday , notification , omen , portent , prediction , premonition , presage , recommendation , sign , signal , sos , suggestion , threat , tip , tip-off , token , watch-it , wink , word , word to the wise , admonishment , monition , alarum , tocsin , auspice , beacon , beware , caveat emptor , denunciation , homily , jeremiad , presentiment , prodrome