opossum

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various nocturnal, usually arboreal marsupials of the family Didelphidae, especially Didelphis marsupialis of the Western Hemisphere, having a thick coat of hair, a long snout, and a long prehensile tail. See Regional Note at possum.
2. n. Any of several similar marsupials of Australia belonging to the family Phalangeridae.

Century Dictionary and Cyclopedia

1. n. An American marsupial mammal of the family Didelphyidæ (which see for technical characters). They have the four kinds of teeth which carnivorous quadrupeds regularly possess (incisors, canines, premolars, and molars), and are omnivorous, eating flesh and carrion, reptiles, insects, and fruits. The head is conical, and the snout somewhat resembles that of a pig; the ears are large, leafy, and rounded; the eyes are small; the whiskers are long; the legs are of proportionate length; both fore and hind paws are five-toed, fashioned like hauds, especially the hind ones, which have an opposable thumb; and the tail is generally long, scaly, and prehensile, so that the animal can hang by it. The pelage is coarse; the body is stout, and in size ranges from that of a large cat to that of a small rat. Most female opossums have on the belly a pouch containing the teats, into which the young are received as soon as they are born. They are born extremely small and imperfect. The Virginia opossum has 13 teats, and no doubt may have as many young at a birth, but the number is usually less. Opossums are nocturnal animals; they move on the ground rather slowly and awkwardly, but are more at home in trees, and some of the species are aquatic. Though they are uncleanly, the flesh is white and palatable, especially in the autumn, when they feed much on fruits, and become as fat as pigs. They commonly appear stupid, and in confinement continue sullen and intractable. When caught or threatened with danger they feign death, and will submit to the most brutal maltreatment without showing a sign of animation, whence the proverbial expression “to play possum.” Most opossums belong to the genus Didelphys, ranging from middle latitudes in the United States through the greater part of South America. The commonest and best-known is D. virginiana. There are perhaps a dozen others, among them pouchless ones, as D. dorsigera. The yapoks or wateropossums of South America form another genus, Chironectes.
2. n. A name of sundry other marsupials: as, the ursine opossum (that is, the ursine dasyure); the vulpine opossum (the vulpine phalangist).

Wiktionary

1. n. zoology Any American marsupial of the genera Didelphys and Chironectes. The common species of the United States is Didelphys virginiana.

GNU Webster's 1913

1. n. (Zoöl.) Any American marsupial of the genera Didelphys and Chironectes; called also possum. The common species of the United States is Didelphys Virginiana.

WordNet 3.0

1. n. nocturnal arboreal marsupial having a naked prehensile tail found from southern North America to northern South America
2. n. small furry Australian arboreal marsupials having long usually prehensile tails