/ Dictionary / Index P piperazine: Meaning and Definition of Find definitions for: pi•per•a•zine Pronunciation: (pi-per'u-zēn", -zin, pī-, pip'ur-u-), [key] — n. Chem. Also calleda colorless, crystalline, deliquescent ring compound, CHN, prepared by the reaction of ethylene bromide or ethylene chloride with ammonia: used chiefly in veterinary medicine as an anthelmintic, and as an insecticide. any derivative of this compound. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: piperazine (Thesaurus) pipe rack piperidine Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language