Buck-in

a sawhorse.
Gymnastics. a cylindrical, leather-covered block mounted in a horizontal position on a single vertical post set in a steel frame, for use chiefly in vaulting.
any of various heavy frames, racks, or jigs used to support materials or partially assembled items during manufacture, as in airplane assembly plants.
Also called door buck. a doorframe of wood or metal set in a partition, especially one of light masonry, to support door hinges, hardware, finish work, etc.
to split or saw (logs, felled trees, etc.).
buck in, Surveying, Optical Tooling. to set up an instrument in line with two marks.
noun

the male of various animals including the goat, hare, kangaroo, rabbit, and reindeer
(as modifier): a buck antelope

(South African) an antelope or deer of either sex
(US, informal) a young man
(archaic) a robust spirited young man
(archaic) a dandy; fop
the act of bucking
verb
(intransitive) (of a horse or other animal) to jump vertically, with legs stiff and back arched
(transitive) (of a horse, etc) to throw (its rider) by bucking
(informal, mainly US & Canadian) when intr, often foll by against. to resist or oppose obstinately: to buck against change, to buck change
(transitive; usually passive) (informal) to cheer or encourage: I was very bucked at passing the exam
(US & Canadian, informal) (esp of a car) to move forward jerkily; jolt
(US & Canadian) to charge against (something) with the head down; butt
noun
(US & Canadian, Austral, informal) a dollar
(South African, informal) a rand
a fast buck, easily gained money
bang for one’s buck, See bang1 (sense 15)
noun
(gymnastics) a type of vaulting horse
(US & Canadian) a stand for timber during sawing Also called (in Britain and certain other countries) sawhorse
verb
(transitive) (US & Canadian) to cut (a felled or fallen tree) into lengths
noun
(poker) a marker in the jackpot to remind the winner of some obligation when his turn comes to deal
(informal) pass the buck, to shift blame or responsibility onto another
(informal) the buck stops here, the ultimate responsibility lies here
noun
Pearl S(ydenstricker). 1892–1973, US novelist, noted particularly for her novel of Chinese life The Good Earth (1931): Nobel prize for literature 1938
n.

The ‘buck’ is any inanimate object, usually knife or pencil, which is thrown into a jack pot and temporarily taken by the winner of the pot. Whenever the deal reaches the holder of the ‘buck’, a new jack pot must be made. [J.W. Keller, “Draw Poker,” 1887]

Perhaps originally especially a buck-handled knife. The figurative sense of “shift responsibility” is first recorded 1912. Buck private is recorded by 1870s, of uncertain signification.
v.

A dollar (1850s+)
A hundred dollars, esp as a bet (1960s+ Gambling)
buck private
A Roman Catholic priest (1920s+ Hoboes)
A young male Indian; Native American brave (1800+)
young black man (1830s+)
Any young man, esp a strong and spirited one; bucko (mid-1700s+)

To resist; defy; go up against •Often in the negative: You can’t buck the system/ Life is a combination hard to buck, A proposition difficult to beat (1850s+)
To work for personal advancement; aspire eagerly; covet: I’m bucking for that dealership (1880s+)
To pass along a letter, memorandum, problem, etc, usually without taking action; pass the buck: Let’s buck this one to the Committee on Hot Potatoes (WWII armed forces)

buck for
buck stops here, the
buck up