Also found in: Dictionary, Thesaurus, Idioms, Encyclopedia, Wikipedia.
1. A modified muscular pouch behind the stomach in the digestive tract of birds, having a thick lining and often containing ingested grit that aids in the breakdown of seeds before digestion.
2. A similar digestive organ found in certain invertebrates, such as the earthworm.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
gizzarda portion of the anterior part of the alimentary canal where food materials are broken up prior to digestion. Usually the gizzard possesses strong muscular walls and in invertebrates has internal projections. In some birds, such as the curlew, the gizzard lining is regularly renewed and the old lining cast out in the form of a pellet.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005