the act of flying while waiting for combat orders or for enemy airplanes to appear.
the signal to take stations for such action.
Origin of air alert
First recorded in 1940–45
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for air alert
the condition in which combat aircraft are airborne and ready for an operation
a signal to prepare for this
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012