/ Dictionary / Index T tautomerism: Meaning and Definition of Find definitions for: tau•tom•er•ism Pronunciation: (tô-tom'u-riz"um), [key] — n. Chem. the ability of certain organic compounds to react in isomeric structures that differ from each other in the position of a hydrogen atom and a double bond. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tautomer tautomerize Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language