cheek pouch

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A pocketlike fold of skin in the cheeks of various animals, such as squirrels, gophers, and monkeys, that functions as a means of carrying food.

Century Dictionary and Cyclopedia

1. n. A special dilatation of the skin or of the skin and mucous membrane of the cheek, forming a pouch or bag outside the teeth, in many animals, as monkeys, squirrels, and various other rodents. An external cheek-pouch is a reduplication of the skin of the cheeks, entirely outside the mouth, lined with fur, forming a bag, as in the rodents of the family Geomyidœ (which see). In the case of ordinary cheek-pouches, the entrance is in the cavity of the mouth; but the opening of external cheek-pouches is entirely outside the mouth.

Wiktionary

1. n. anatomy, zoology A pouch in the cheek of some animals, usually used to carry food.

GNU Webster's 1913

1. n. (Zoöl.) a sacklike dilation of the cheeks of certain monkeys and rodents, used for holding food.

WordNet 3.0

1. n. a membranous pouch inside the mouth of many rodents (as a gopher)