/ Dictionary / Index O orthocenter: Meaning and Definition of Find definitions for: or•tho•cen•ter Pronunciation: (ôr'thu-sen"tur), [key] — n. Geom. the point of intersection of the three altitudes of a triangle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. orthoboric acid orthocephalic Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language