/ Dictionary / Index P propanil: Meaning and Definition of Find definitions for: pro•pa•nil Pronunciation: (prō'pu-nil), [key] — n. Chem. a postemergence herbicide, CHClNO, used for weed control on potatoes, rice, and other crop plants. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. propanedioic propanoic acid Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language