/ Dictionary / Index M mEq: Meaning and Definition of Find definitions for: mEq Pronunciation: [key] milliequivalent. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: meq (Thesaurus) meprobamate Mequon Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language