warning -- (a message informing of danger; "a warning that still more bombs could explode")
admonition, monition, warning, word of advice -- (cautionary advice about something imminent (especially imminent danger or other unpleasantness); "a letter of admonition about the dangers of immorality"; "the warning was to beware of surprises"; "his final word of advice was not to play with matches")
warning -- (notification of something, usually in advance; "they gave little warning of their arrival"; "she had only had four days' warning before leaving Berlin")
Overview of verb warn
The verb warn has 4 senses
warn -- (notify of danger, potential harm, or risk; "The director warned him that he might be fired"; "The doctor warned me about the dangers of smoking")
warn, discourage, admonish, monish -- (admonish or counsel in terms of someone's behavior; "I warned him not to go too far"; "I warn you against false assumptions"; "She warned him to be quiet")
warn -- (ask to go away; "The old man warned the children off his property")
warn -- (notify, usually in advance; "I warned you that I would ask some difficult questions")