hamster

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A small Eurasian rodent of the subfamily Cricetinae, especially Mesocricetus auratus, having large cheek pouches and a short tail and often kept as a pet or used in laboratory research.

Century Dictionary and Cyclopedia

1. n. A murine or myomorphic rodent quadruped, of the family Muridœ and subfamily Cricetinæ, and of one of the genera Cricetus, Cricetomys, and Saccostomus. They are furnished with cheek-pouches, which are the principal distinctive character of the group in comparison with other Muridæ. The common hamster, Cricetus frumentarius, inhabits parts of Europe and Asia. It is a stout little animal about 10 inches long, with a short hairy tail. It is variegated in color (black on the under parts), burrows deeply in the ground, stores its galleries with grain, and hibernates during the colder months. It is very prolific, and readily breeds in confinement. The fur is poor, short, and coarse, but is sometimes used for the lining of cloaks. The other genera above named are African.
2. n. Some other pouched rodent, as of the genus Geomys, more or less resembling a hamster.

Wiktionary

1. n. A small, short-tailed Euroasian rodent, Cricetus frumentarius, often kept as a pet. It is remarkable for having a pouch on each side of the jaw, under the skin, and for its migrations.
2. n. zoology Any of various Old-world rodent species belonging to the subfamily Cricetinae.

GNU Webster's 1913

1. n. (Zoöl.) A small European rodent (Cricetus frumentarius). It is remarkable for having a pouch on each side of the jaw, under the skin, and for its migrations. Hamsters are commonly kept as a pets.

WordNet 3.0

1. n. short-tailed Old World burrowing rodent with large cheek pouches