/ Dictionary / Index M malathion: Meaning and Definition of Find definitions for: mal•a•thi•on Pronunciation: (mal"u-thī'on, -un), [key] an organic phosphate insecticide, CHOSP, of relatively low toxicity for mammals. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: malathion (Thesaurus) malate Malatya Related Content Daily Word Quiz: nonchalant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language