O.E.
bula "a steer," or O.N.
boli "bull," both from P.Gmc.
*bullon- (cf. M.Du.
bulle, Ger.
Bulle), perhaps from a Gmc. verbal stem meaning "to roar," which survives is some Ger. dialects and perhaps in the first element of
boulder (q.v.). The other possibility is that it is from PIE
*bhel- "to inflate, swell" (the source also of the Gk. word for "whale;" see
bole). An uncastrated male, reared for breeding, as opposed to a
bullock or
steer. Extended after 1615 to males of other large animals (elephant, alligator, whale, etc.). Stock market sense is from 1714.
Bulldog is from 1500, perhaps from shape, perhaps originally used for baiting bulls;
bullfrog is from 1738, on resemblance of voice.
Bulldyke is from 1926 (see
dyke).
Bull's eye "center of a target" is from 1833.
Bullpen in the baseball sense is first recorded 1915, perhaps from earlier slang meaning "temporary holding cell for prisoners" (1809). Phrase
to take the bull by the horns first recorded 1711.
