c.1300, "a wedge," from Old French coing (12c.) "a wedge; stamp; piece of money; corner, angle," from Latin cuneus "a wedge." The die for stamping metal was wedge-shaped, and the English word came to mean "thing stamped, a piece of money" by late 14c. (a sense that already had developed in French). Cf. quoin, which split off from this word 16c. Modern French coin is "corner, angle, nook." Coins were first struck in western Asia Minor in 7c. B.C.E.; Greek tradition and Herodotus credit the Lydians with being first to make and use coins of silver and gold.
"to coin money," mid-14c., from coin (n.). Related: Coined; coining. To coin a phrase is late 16c. A Middle English word for minter was coin-smiter.