reindeer

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A large deer (Rangifer tarandus) of the Arctic and northern regions of Eurasia and North America, having branched antlers in both sexes.

Century Dictionary and Cyclopedia

1. n. A deer of the genus Rangifer or Tarandus, having horns in both sexes, and inhabiting arctic and cold temperate regions; the Cervus tarandus, Rangifer tarandus, or Tarandus rangifer. It has branched, recurved, round antlers, the crowns of which are more or less palmated; the antlers of the male are much larger than those of the female, and are remarkable for the size and asymmetry of the brow-antler. The body is of a thick and square form, and the legs are shorter in proportion than those of the red-deer. The size varies much according to climate: about 4 feet 6 inches may be given as the average height of a full-grown specimen. The reindeer is keen of sight and swift of foot being capable of maintaining a speed of 9 or 10 miles an hour for a long time, and can easily draw a weight of 200 pounds, besides the sledge to which it is usually attached when used as a beast of draft. Among the Laplanders the reindeer is a substitute for the horse, the cow, and the sheep, as it furnishes food, clothing, and the means of conveyance. The caribou of North America, if not absolutely identical with the reindeer, would seem to be at least a well-marked variety, usually called R. caribou. The American barrenground reindeer has been described as a different species, R. grœnlandicus. See also cut under caribou.
2. n. In heraldry, a stag having two sets of antlers, the one pair bending downward, and the other standing erect.

Wiktionary

1. n. zoology An Arctic and Subarctic-dwelling deer with a number of subspecies. The North American subspecies are known as caribou.

GNU Webster's 1913

1. n. (Zool.) Any ruminant of the genus Rangifer, of the Deer family, found in the colder parts of both the Eastern and Western hemispheres, and having long irregularly branched antlers, with the brow tines palmate.

WordNet 3.0

1. n. Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America