/ Dictionary / Index I immune serum: Meaning and Definition of Find definitions for: immune' se'rum Pronunciation: [key] a serum containing naturally or artificially produced antibodies to a given antigen, obtained from human or animal sources. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. immune response immune system 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