any of various small, nocturnal, long-tailed mice (family Heteromyidae) with fur-lined cheek pouches for carrying food to their burrows: found in W and SW North America
See pocket mouse in American Heritage Dictionary 4
noun
Any of various small, nocturnal North American burrowing rodents of the genus Perognathus, related to the kangaroo rat and having fur-lined external cheek pouches, small ears, and a long tail.