Coupling pin

(Mech.) The pin used in coupling railroad-cars, ., together. Coupon, ( koo'pon ,) n. [Fr.] ( Com .) A voucher, or certificate of interest on a bond payable by instalments, affixed in a series at the foot of the bond, and cut off for presentation when the instalments shall respectively become due; as, the coupon of a railroad debenture.