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PIN (pĭn)
personal identification number

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
pin (pĭn)
a. A short, straight, stiff piece of wire with a blunt head and a sharp point, used especially for fastening.
b. Something, such as a safety pin, that resembles such a piece of wire in shape or use.
c. A whit; a jot: didn't care a pin about the matter.
2. A slender, usually cylindrical piece of wood or metal for holding or fastening parts together, or serving as a support for suspending one thing from another, as:
a. A thin rod for securing the ends of fractured bones.
b. A peg for fixing the crown to the root of a tooth.
c. A cotter pin.
d. The part of a key stem entering a lock.
e. Music One of the pegs securing the strings and regulating their tension on a stringed instrument.
f. Nautical A belaying pin.
g. Nautical A thole pin.
3. An ornament fastened to clothing by means of a clasp.
4. A rolling pin.
5. Sports
a. One of the wooden clubs at which the ball is aimed in bowling.
b. A flagstick.
c. See fall.
6. pins Informal The legs: is steady on his pins.
7. Electronics A lead on a device that plugs into a socket to connect the device to a system.
8. Computers
a. Any of the pegs on the platen of a printer, which engage holes at the edges of paper.
b. Any of the styluses that form a dot matrix on a printer.
c. Any of the small metal prongs at the end of a connector that fit into the holes in a port.
tr.v. pinned, pin·ning, pins
1. To fasten or secure with or as if with a pin or pins.
2. To transfix.
3. To place in a position of trusting dependence: He pinned his faith on an absurdity.
a. To hold fast; immobilize: He was pinned under the wreckage of the truck.
b. Sports To win a fall from in wrestling.
5. To give (a woman) a fraternity pin in token of attachment.
Having a grain suggestive of the heads of pins. Used of leather.
Phrasal Verbs:
pin down
1. To fix or establish clearly: She pinned down the cause of the accident.
2. To force (someone) to give firm opinions or precise information: The reporter pinned the governor down on the issue of taxes.
pin on
To attribute (a crime) to (someone): The murder was pinned on the wrong suspect.

[Middle English, from Old English pinn, perhaps from Latin pinna, feather; see pet- in the Appendix of Indo-European roots.]

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.

Indo-European & Semitic Roots Appendices

    Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

    Indo-European Roots

    Semitic Roots

    The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.