buck

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

• noun A male deer.
• noun The male of various other mammals, such as antelopes, kangaroos, mice, or rabbits.
• noun Antelope considered as a group.
• noun A robust or high-spirited young man.
• noun A fop.
• noun Offensive A Native American or black man.
• noun An act or instance of bucking.
• noun Buckskin.
• noun Buckskin breeches or shoes.
• intransitive verb To leap upward arching the back.
• intransitive verb To charge with the head lowered; butt.
• intransitive verb To make sudden jerky movements; jolt.
• intransitive verb To resist stubbornly and obstinately; balk.
• intransitive verb Informal To strive with determination.
• intransitive verb To throw or toss by bucking.
• intransitive verb To oppose directly and stubbornly; go against.
• intransitive verb Football To charge into (an opponent's line) carrying the ball.
• intransitive verb To butt against with the head.
• adjective Of the lowest rank in a specified military category.
• noun A sawhorse or sawbuck.
• noun A leather-covered frame used for gymnastic vaulting.
• noun Games A counter or marker formerly passed from one poker player to another to indicate an obligation, especially one's turn to deal.
• noun Informal Obligation to account for something; responsibility.
• transitive verb To pass (a task or duty) to another, especially so as to avoid responsibility.
• idiom (the buck stops here) The ultimate responsibility rests here.
• noun A dollar.
• noun An amount of money.

from The Century Dictionary.

• To copulate, as bucks and does.
• To butt: a sense referred also to buck 4 (which see).
• noun A violent effort of a horse or mule to rid itself of its rider or burden; the act of bucking.
• To soak or steep (clothes) in lye, as in bleaching; wash in lye or suds; clean by washing and beating with a bat.
• To bend; buckle.
• To spring lightly.
• To make a violent effort to throw off a rider or pack, by means of rapid plunging jumps performed by springing into the air, arching the back, and coming down with the fore legs perfectly stiff, the head being commonly held as low as possible: said of a horse or a mule.
• To “kick”; make obstinate resistance or objection: as, to buck at improvements.
• To punish by tying the wrists together, passing the arms over the bent knees, and putting a stick across the arms and in the angle formed by the knees.
• To throw, or attempt to throw (a rider), by bucking: as, the bronco bucked him off.
• noun A he-goat.
• noun The male of the deer, the antelope, the rabbit, or the hare: often used specifically of the male of the fallow-deer; a roebuck.
• noun A gay or fashionable man; a fop; a blood; a dandy.
• noun A male Indian.
• noun A male negro.
• noun The mark of a cuckold.
• noun Lye in which clothes are soaked in the operation of bleaching; the liquor in which clothes are washed.
• noun The cloth or clothes soaked or washed in lye or suds; a wash.
• noun The breast.