/ Dictionary / Index I IgD: Meaning and Definition of Find definitions for: IgD Pronunciation: [key] — Immunol. Immunol. immunoglobulin D: a class of antibodies present as an antigen receptor on most cell surfaces and predominant on human B cells. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: igd (Thesaurus) Igbo IgE Related Content Daily Word Quiz: penury Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language