/ Dictionary / Index B blue alert: Meaning and Definition of Find definitions for: blue' alert' Pronunciation: [key] (in military or civilian defense) an alert following the first, or yellow, alert, in which air attack seems probable. Cf. red alert, white alert, yellow alert. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. blue blue angel Related Content Daily Word Quiz: blanch Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language