1. part of bird's stomach: the first part of a bird's stomach, where digestive enzymes are mixed with food before it goes to the gizzard. It is analogous to the gizzard in insects and crustaceans.
2. part of invertebrate's stomach: the thin-walled section of the stomach of some invertebrates
3. part of insect's stomach: the part of the foregut in some insects that has teeth or plates for grinding food