—n. 1. a small, slender, often pointed piece of wood, metal, etc., used to fasten, support, or attach things.
2. a short, slender piece of wire with a point at one end and a head at the other, for fastening things together.
3. any of various forms of fasteners or ornaments consisting essentially or partly of a pointed or penetrating wire or shaft (often used in combination): a jeweled pin. 4. a badge having a pointed bar or pin attached, by which it is fastened to the clothing: a fraternity pin. 5. Mach. a. a short metal rod, as a linchpin, driven through holes in adjacent parts, as a hub and an axle, to keep the parts together.
b. a short cylindrical rod or tube, as a wrist pin or crankpin, joining two parts so as to permit them to move in one plane relative to each other.
c. a short axle, as one on which a pulley rotates in a block.
6. the part of a cylindrical key stem entering a lock.
7. a clothespin.
8. a hairpin.
9. See rolling pin. 10. a peg, nail, or stud marking the center of a target.
11. Bowling.any one of the rounded wooden clubs set up as the target in tenpins, ninepins, duckpins, etc.
12. Golf.the flag staff which identifies a hole.
13. any of the projecting knobs or rails on a pinball machine that serve as targets for the ball.
14. Informal.a human leg.
15. Music.peg (def. 5).
16. Wrestling.a fall.
17. Naut. a. an axle for a sheave of a block.
b. See belaying pin. 18. Carpentry.a tenon in a dovetail joint; dovetail.
19. a very small amount; a trifle: Such insincere advice isn't worth a pin. 20. Chess.the immobilization of an enemy piece by attacking with one's queen, rook, or bishop.
21. Electronics.a pin-shaped connection, as the terminals on the base of an electron tube or the connections on an integrated circuit.
22. pull the pin,Informal.to end a relationship, project, program, or the like, because of lack of continuing interest, success, funds, etc.
—v.t. 1. to fasten or attach with or as with a pin or pins: to pin two pieces of cloth together. 2. to hold fast in a spot or position (sometimes fol. by down): The debris pinned him down. 3. to transfix or mount with a pin or the like: to pin a flower as a botanical specimen. 4. Chess.to immobilize (an enemy piece) by placing one's queen, rook, or bishop in a position to check the exposed king or capture a valuable piece if the pinned piece were moved.
5. Wrestling.to secure a fall over one's opponent.
6. get pinned, a. (of a young woman) to receive a male student's fraternity pin as a symbol of his affection and fidelity, usually symbolizing that the couple is going steady or plans to become engaged.
b. (of a young couple) to become formally pledged to one another, though not yet engaged, by the bestowing of such a pin or the exchange of pins.
7. pin down, a. to bind or hold to a course of action, a promise, etc.
b. to force (someone) to deal with a situation or to come to a decision: We tried to pin him down for a definite answer, but he was too evasive for us. 8. pin in, to fill (gaps in a rubble wall, etc.) with spalls.
9. pin something on someone,Informal.to ascribe the blame or guilt for something to a person; show someone to be culpable: They pinned the crime on him. 10. pin up, to make (a piece of masonry) level or plumb with wedges.
Pronunciation: (pin),[key] —n.Computers. a number assigned to an individual, used to establish identity in order to gain access to a computer system via an automatic teller machine, a point-of-sale terminal, or other device.