Pronunciation: (kOO'pon, kyOO'-),[key] —n. 1. a portion of a certificate, ticket, label, advertisement, or the like, set off from the main body by dotted lines or the like to emphasize its separability, entitling the holder to something, as a gift or discount, or for use as an order blank, a contest entry form, etc.
2. a separate certificate, ticket, etc., for the same purpose.
3. one of a number of small detachable certificates calling for periodic interest payments on a bearer bond. Cf. coupon bond. 4. Metall.a sample of metal or metalwork submitted to a customer or testing agency for approval.