Coupon
I was in the car talking and realized the word coupon sounded a bit strange. It did not sound like an English word at all. I thought it sounded French. So needless to say I looked up the word and it is indeed a stolen French word.
Coupon
1822- Certificate of interest due, a piece of paper cut off. If anyone is old enough to remember, it perfectly describes a coupon payment book one had to send in with a payment on a loan.
1860- expanded use of the word as a discount ticket.
1906- financial discount
Taken from the etymonline.com