/ Dictionary / Index I Ig: Meaning and Definition of Find definitions for: Ig Pronunciation: [key] immunoglobulin. I.G. Pronunciation: [key] Indo-Germanic. Inspector General. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ig (Thesaurus) -ify IgA Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language