/ Dictionary / Index P pro-oestrus: Meaning and Definition of Find definitions for: pro-oes•trus Pronunciation: (prō-es'trus, -ē'strus), [key] — n. proestrus. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. prony brake proof Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language