/ Dictionary / Index A allethrin: Meaning and Definition of Find definitions for: al•le•thrin Pronunciation: (al'u-thrin), [key] — n. Chem. a clear, amber, viscous liquid, CHO, used as an insecticide. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. allergy alleviant Related Content Daily Word Quiz: candor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language