/ Dictionary / Index I isomer: Meaning and Definition of Find definitions for: i•so•mer Pronunciation: (ī'su-mur), [key] — n. a compound displaying isomerism with one or more other compounds. Also calleda nuclide that exhibits isomerism with one or more other nuclides. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: isomer (Thesaurus) isomagnetic isomerase 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