/ Dictionary / Index E ECM: Meaning and Definition of Find definitions for: ECM Pronunciation: [key] electronic countermeasures. European Common Market. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ecm (Thesaurus) eclosion eco- Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language