wake-up call a telephone call that you request be made a specific time in order to wake you up at that time (especially in hotels); "she left a wake-up call for 7 a.m."
alerting,
alert a warning serves to make you more alert to danger
caveat,
caution (law) a formal notice filed with a court or officer to suspend a proceeding until filer is given a hearing; "a caveat filed against the probate of a will"
false alarm a warning that is given about something that fails to occur
heads-up a warning message; "he sent a heads-up to the District Attorney"
strategic warning (military) a warning prior to the start of a threatening act
tactical warning (military) a warning after the initiation of a hostile act
warning -
notification of something, usually in advance; "they gave little warning of their arrival"; "she had only had four days' warning before leaving Berlin"
warning -
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"
