/ Dictionary / Index O orthonormal: Meaning and Definition of Find definitions for: or•tho•nor•mal Pronunciation: (ôr"thu-nôr'mul), [key] — adj. Math. (of a system of functions) normal; normalized. (of a set of vectors) having the properties that any two vectors are perpendicular and that each vector has a length of one unit. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ortho-nitrophenol Ortho-Novum Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language