/ Dictionary / Index U ultimo: Meaning and Definition of Find definitions for: ul•ti•mo Pronunciation: (ul'tu-mō"), [key] — adv. in or of the month preceding the current one:ult., ulto. Cf.(def. 11), on the 12th ultimo. Abbr.: Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ultimo (Thesaurus) ultimatum ultimogeniture Related Content Daily Word Quiz: philanthropy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language