/ Dictionary / Index P pseudoephedrine: Meaning and Definition of Find definitions for: pseu•do•e•phed•rine Pronunciation: (s"dō-i-fed'rin, -ef'i-drēn", -drin), [key] — n. Pharm. a dextrorotatory, isomeric compound, CHNO, used as a nasal decongestant. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pseudoephedrine (Thesaurus) pseudodipteral pseudo-event 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