caribou vs. deer

noun

plural caribous, (especially collectively) caribou.
  1. any of several large, North American deer of the genus Rangifer, related to the reindeer of the Old World.


noun

plural deer, (occasionally) deers.
  1. any of several ruminants of the family Cervidae, most of the males of which have solid, deciduous antlers.
  2. any of the smaller species of this family, as distinguished from the moose, elk, etc.