/ Dictionary / Index I isomerase: Meaning and Definition of Find definitions for: i•som•er•ase Pronunciation: (ī-som'u-rās", -rāz"), [key] — n. Biochem. any of a class of enzymes that catalyze reactions involving intramolecular rearrangements. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: isomerase (Thesaurus) isomer isomeric Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language