Pronunciation: (koin),[key] —n. 1. a piece of metal stamped and issued by the authority of a government for use as money.
2. a number of such pieces.
3. Informal.money; cash: He's got plenty of coin in the bank. 4. Archit.quoin (defs. 1, 2).
5. Archaic.a corner cupboard of the 18th century.
6. pay someone back in his or her own coin, to reciprocate or behave toward in a like way, esp. inamicably; retaliate: If they persist in teasing you, pay them back in their own coin. 7. the other side of the coin, the other side, aspect, or point of view; alternative consideration.
—adj. operated by, or containing machines operated by, inserting a coin or coins into a slot: a coin laundry.
—v.t. 1. to make (coinage) by stamping metal: The mint is coining pennies. 2. to convert (metal) into coinage: The mint used to coin gold into dollars. 3. to make; invent; fabricate: to coin an expression. 4. Metalworking.to shape the surface of (metal) by squeezing between two dies. Cf. emboss (def. 3).
—v.i. 1. Brit. Informal.to counterfeit, esp. to make counterfeit money.
2. coin money,Informal.to make or gain money rapidly: Those who own stock in that restaurant chain are coining money.