Rain·deer n. Zool. See Reindeer. [Obs.]
Rein·deer n. [Formerly written also raindeer, and ranedeer.] 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.
Note: ☞ The common European species (Rangifer tarandus) is domesticated in Lapland. The woodland reindeer or caribou (Rangifer caribou) is found in Canada and Maine (see Caribou.) The Barren Ground reindeer or caribou (Rangifer Groenlandicus), of smaller size, is found on the shores of the Arctic Ocean, in both hemispheries.
Reindeer moss Bot., a gray branching lichen (Cladonia rangiferina) which forms extensive patches on the ground in arctic and even in north temperature regions. It is the principal food of the Lapland reindeer in winter.
Reindeer period Geol., a name sometimes given to a part of the Paleolithic era when the reindeer was common over Central Europe.