/ Dictionary / Index I isostructural: Meaning and Definition of Find definitions for: i•so•struc•tur•al Pronunciation: (ī"su-struk'chur-ul), [key] — adj. Crystall. (of two substances) having the same crystal structure but not necessarily a similar chemical composition. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. isosterism isotac 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