n. pl. reindeer or rein·deers
A large deer (Rangifer tarandus) of the Arctic tundra and northern boreal forests, having large hooves and long branched antlers in both sexes, and widely domesticated in Eurasia. Subspecies native to North America and Greenland are usually called caribou.
[Middle English reindere : Old Norse hreinn, reindeer; see ker-1 in the Appendix of Indo-European roots + Middle English der, animal; see DEER.]
Word History: The word reindeer has nothing to do with reins. The element -deer in reindeer is indeed our word deer, but the element rein- has a different origin. Rein, "leather strap for guiding animals," comes from Old French resne, while the rein- in reindeer is of Scandinavian origin. Wild reindeer once roamed Great Britain in prehistoric times, but they had become extinct long before the Anglo-Saxons invaded the island, or even before the Celts settled it in ancient times. (The small herd of wild reindeer that currently lives in Scotland descends from animals imported from Scandinavia.) To most people in medieval England and Scotland, the reindeer was a foreign creature living in distant Scandinavia, and it is therefore not surprising that the English name of this animal contains an element borrowed from a Scandinavian source. The rein- in Middle English reindere (Modern English reindeer) comes from the Old Norse word for the reindeer, hreinn.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus