Английский Этимологический словарь - pin (n.)

- O.E. pinn "peg, bolt," from P.Gmc. *penn- "jutting point or peak," or possibly from L. pinna "wing, feather," also used for "pointed peak." The modern slender wire pin emerged in M.E. Transfered sense of "leg" is from 1530. Pin-up (adj.) is from 1941. Pinwheel is from 1696, "a wheel in the striking train of a clock in which pins are fixed to lift the hammer;" catherine-wheel sense is from 1869.