pinpinpins1nouna small thin piece of metal with a flat part at one end and a sharp point at the other. You use a pin for holding things together or fixing one thing to another.Look also at drawing pin and safety pin.pinpinpinspinnedpinning2verb (pins, pinning, pinned)1to fix things together with a pin or pins: Could you pin this notice to the board?2to hold somebody or something so that they cannot move: He tried to get away, but they pinned him against the wall.