/ Dictionary / Index O oral hygiene: Meaning and Definition of Find definitions for: o'ral hy'giene Pronunciation: [key] the state or practice of keeping the mouth cavity in a healthy condition, as by a regular program of brushing and flossing the teeth combined with periodic examinations by a dentist. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. oral history oral interpretation Related Content Daily Word Quiz: exemplary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language