/ Dictionary / Index A active immunity: Meaning and Definition of Find definitions for: ac'tive immu'nity Pronunciation: [key] — Immunol. Immunol. immunity in an organism resulting from its own production of antibody or lymphocytes. Cf. passive immunity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. active hydrogen active layer Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language