proventriculus

The division of the stomach in birds that secretes digestive enzymes and passes food from the crop to the gizzard.

A similar digestive chamber in certain insects and worms.

In ornithology, the glandular stomach; a second dilatation of the esophagus, succeeding the crop or craw, and succeeded by the gizzard, gigerium, or muscular stomach.

In insects, the first stomach, the ingluvies or crop, being merely an expansion of the esophagus.

In worms, a muscular crop.

The part of the avian stomach, between the crop and the gizzard, that secretes digestive enzymes

A similar part of the digestive system of invertebrates