/ Dictionary / Index I Isiac: Meaning and Definition of Find definitions for: Is•i•ac Pronunciation: (is'ē-ak", iz'-, ī'sē-), [key] — adj. of or pertaining to Isis or the worship of Isis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Ishvara isidioid Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language