/ Dictionary / Index G gamma globulin: Meaning and Definition of Find definitions for: gam'ma glob'ulin Pronunciation: [key] — Immunol. Immunol. a protein fraction of blood plasma that responds to stimulation of antigens, as bacteria or viruses, by forming antibodies: administered therapeutically in the treatment of some viral diseases. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gamma-aminobutyric acid gammagram Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language