Noun has 3 senses

• air alert(n = noun.time) - the time period during which military and civilian agencies are prepared for an enemy air attack;


• air alert(n = noun.state) - the condition in which combat aircraft are airborne and ready for an operation; "aircraft in the Mideast are on air alert"


• air alert(n = noun.communication) - the warning signal that begins a period of preparation for an enemy air attack;