Origin and history of beaver

"large carnivorous or omnivorous mammal of the family Ursidae," Old English bera "a bear," from Proto-Germanic *bero, literally "the brown (one)" (source also of Old Norse björn, Middle Dutch bere, Dutch beer, Old High German bero, German Bär), usually said to be from PIE root *bher- (2) "bright; brown." There was perhaps a PIE *bheros "dark animal" (compare beaver (n.1) and Greek phrynos "toad," literally "the brown animal").

Greek arktos and Latin ursus retain the PIE root word for "bear" (*rtko; see arctic), but it is believed to have been ritually replaced in the northern branches because of hunters' taboo on names of wild animals (compare the Irish equivalent "the good calf," Welsh "honey-pig," Lithuanian "the licker," Russian medved "honey-eater"). Others connect the Germanic word with Latin ferus "wild," as if it meant "the wild animal (par excellence) of the northern woods."

Used of rude, gruff, uncouth men since 1570s. Symbolic of Russia since 1794. The stock market meaning "speculator for a fall" is by 1709, a shortening of bearskin jobber (from the proverb sell the bearskin before one has caught the bear); i.e. "one who sells stock for future delivery, expecting that meanwhile prices will fall." Paired with bull from c. 1720. Bear claw as a type of large pastry is from 1942, originally chiefly western U.S. Bear-garden (1590s) was a place where bears were kept for the amusement of spectators.

late 14c., "a beaver," from Old French castor (13c.), from Latin castor "beaver," from Greek kastor "beaver," perhaps literally "he who excels," and thus identical with the name of one of the divine twins (with Pollux), worshipped by women in ancient Greece as a healer and preserver from disease (see Castor).

It has been assumed that the hero's name was given to the animal because he was a noted healer and the odorous reddish-brown secretions of the inguinal sacs of the animal (Latin castoreum), were used medicinally in ancient times, especially for women's diseases. But the animal did not live in Greece in classical times (the closest beavers were north of the Black Sea), and the name probably was borrowed from another language, perhaps influenced by the hero's name. The Greek word replaced the native Latin word for "beaver" (fiber).

In English, castor is attested in the secretion sense from late 14c. Modern castor oil is so-called by 1746; it is made from seeds of the plant Ricinus communis but supposedly possesses the laxative qualities (and taste) of beaver juice.