bursa of Fabricius: Meaning and Definition of

bur'sa of Fabri'cius

Pronunciation: [key]
— Ornith. Ornith.
  1. a lymphoid gland of the cloaca in birds, believed to function in disease resistance, and closing or disappearing as the bird ages.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.