The definition of a bruin is a bear.(noun)
An example of a bruin is the mascot of the Boston hockey team, the Blades.
See Bruin in Webster's New World College Dictionary
Origin: Du, brown
See Bruin in American Heritage Dictionary 4
Origin: Middle English
Origin: , name of the bear in History of Reynard the Fox, translated by William Caxton
Origin: from Middle Dutch bruun, bruin, brown, name of the bear in the Middle Dutch version of the fable; see bher-2 in Indo-European roots.
Learn more about Bruin