A Voucher

1. A piece of paper that entitles the holder to a discount, or that can be exchanged for goods and services.
2. A receipt.
3. One who or that which vouches.
4. (advertising) A copy of a published advertisement sent by the agency to the client as proof of publication.
5. (historical) A mechanical device used in shops for automatically registering the amount of money drawn.

Synonyms

• (piece of paper that entitles the holder to a discount): coupon