bull

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A gross blunder in logical speech or expression.
• noun An adult male bovine mammal.
• noun The uncastrated adult male of domestic cattle.
• noun The adult male of certain other large animals, such as alligators, elephants, moose, or whales.
• noun An exceptionally large, strong, and aggressive person.
• noun An optimist, especially regarding business conditions.
• noun A person who buys commodities or securities in anticipation of a rise in prices or who tries by speculative purchases to effect such a rise.
• noun Slang A police officer or detective.
• noun Foolish, deceitful, or boastful language.
• noun Insolent talk or behavior.
• intransitive verb To push; force.
• intransitive verb To push ahead or through forcefully.
• adjective Male.
• adjective Large and strong like a bull.
• adjective Characterized by rising prices.
• idiom (grab/take) To deal with a problem directly and resolutely.
• noun An official document issued by the pope and sealed with a bulla.
• noun The bulla used to seal such a document.

from The Century Dictionary.

• noun A gross inconsistency in language; a ludicrous blunder involving a contradiction in terms: commonly regarded as especially characteristic of the Irish, and often called an Irish bull.
• noun Synonyms Error, Mistake, etc. See blunder.
• noun The male of the domestic bovine, of which the female is a cow; in general, the male of any bovine, as of the different species of the genus Bos.
• noun An old male whale, sea-lion, sea-bear, or fur-seal.
• noun [capitalized] Taurus, one of the twelve signs of the zodiac.
• noun In stock-exchange slang, one who endeavors to effect a rise in the price of stock: the opposite of a bear. See bear, 5.
• noun The bull's-eye of a target.
• noun plural The stems of hedge-thorns.
• noun plural The transverse bars of wood into which the heads of harrows are set.
• noun A five-shilling piece.
• noun A small keg.
• noun The weak grog made by pouring water into a spirit-cask nearly empty.
• noun Same as bulla, 2.
• noun The most authoritative official document issued by the pope or in his name: usually an open letter containing some decree, order, or decision relating to matters of grace or justice.
• noun An official letter; an edict; especially, an imperial edict under the Roman or the old German empire.
• noun A bubble.
• noun In mining, an iron rod used in ramming clay to line a shot-hole.
• noun Same as beal.
• To toss or throw up (hedges), as cattle do.
• In the stock exchange, to endeavor to raise, as the price of shares, artificially and unduly. See the noun.
• In the stock exchange, in the interest of or favorable to the bulls; buoyant; rising: as, a bull movement; a bull market.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) The male of any species of cattle (Bovidæ); hence, the male of any large quadruped, as the elephant; also, the male of the whale.
• noun One who, or that which, resembles a bull in character or action.
• noun Taurus, the second of the twelve signs of the zodiac.
• noun A constellation of the zodiac between Aries and Gemini. It contains the Pleiades.
• noun (Stock Exchange) One who operates in expectation of a rise in the price of stocks, or in order to effect such a rise. See 4th Bear, n., 5.
• noun vulgar a ludicrously false statement; nonsense. Also used as an expletive.
• noun the practice of baiting bulls, or rendering them furious, as by setting dogs to attack them.