/ Dictionary / Index C chlorpyrifos: Meaning and Definition of Find definitions for: chlor•pyr•i•fos Pronunciation: (klôr-pir'u-fos", klōr-), [key] — n. a broad-spectrum insecticide, CHClNOPS, used on lawns and ornamental plants. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: chlorpyrifos (Thesaurus) chlorpropamide chlortetracycline Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language