/ Dictionary / Index H histaminase: Meaning and Definition of Find definitions for: his•tam•i•nase Pronunciation: (hi-stam'u-nās", -nāz"), [key] — n. Biochem., Pharm. an enzyme that catalyzes the decomposition of histamine, used in treating allergies. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: histaminase (Thesaurus) Histadrut histamine Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language