/ Dictionary / Index M memo: Meaning and Definition of Find definitions for: mem•o Pronunciation: (mem'ō), [key] — pl. mem•os. memorandum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: memo (Thesaurus) Memnonia memoir Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language