/ Dictionary / Index D DEFCON: Meaning and Definition of Find definitions for: DEFCON Pronunciation: (def'kon), [key] — n. any of several alert statuses for U.S. military forces, ranked numerically from normal, 5, to maximum readiness, 1. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. defaulter defeasance Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language