/ Dictionary / Index S secobarbital: Meaning and Definition of Find definitions for: sec•o•bar•bi•tal Pronunciation: (sek"ō-bär'bi-tôl", -tal"), [key] — n. Pharm. a white, odorless, slightly bitter powder, CHNO, used as a sedative and hypnotic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: secobarbital (Thesaurus) seclusive Seconal Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language