/ Dictionary / Index O olefin: Meaning and Definition of Find definitions for: o•le•fin Pronunciation: (ō'lu-fin), [key] — n. Chem. any member of the alkene series. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: olefin (Thesaurus) olefiant gas olefin fiber Related Content Daily Word Quiz: philanthropy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language