/ Dictionary / Index S summum bonum*: Meaning and Definition of Find definitions for: sum•mum bo•num Pronunciation: (soom'oom bō'noom Eng. sum'&schwam bō'n&schwam), [key] — Latin. Latin. the highest or chief good. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. summons Sumner Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language