ETYM Old Eng. pinne, as. pinn a pin, peg.
1. A piece of jewelry that is pinned onto the wearer's garment.
2. A small slender (often pointed) piece of wood or metal used to support or fasten or attach things, especially in sewing.
3. Flagpole used to mark the position of the hole on a golf green; SYN. flag.
4. Informal terms of the leg; SYN. peg, stick.
5. Two-part cylindrical tumblers held in place by springs; when they are aligned with a key the bolt can be thrown.

1. To attach or fasten with pins.
2. To attach with or as if with a pin; SYN. pin down, pin up.
3. To immobilize a piece, in chess.
4. To pierce with a pin

A club-shaped wooden object; set up in groups as a target; SYN. bowling pin.

A slender prong. Pins are commonly encountered as the contacts protruding from a male connector. Connectors are often identified by the number of pins they have. Other types of pins are the spidery, leglike metal appendages that connect computer chips to sockets on a circuit board or directly to the circuit board. See the illustration.

Stands for personal identification number, a unique identifier used together with a personal identification device (PID).
A unique code number used to gain access to personal information or assets via an electronic device. PINs are used by a variety of electronic services such as automated bank tellers, Internet sites, and wireless phone services.
In banking, a unique number used as a password to establish the identity of a customer using an automatic cash dispenser. The PIN is normally encoded into the magnetic strip of the customer's bank card and is known only to the customer and to the bank's computer. Before a cash dispenser will issue money or information, the customer must insert the card into a slot in the machine (so that the PIN can be read from the magnetic strip) and enter the PIN correctly at a keyboard. This effectively prevents stolen cards from being used to obtain money from cash dispensers.