n. One of the stamps that you get (as from a store or gas station) because you buy something there; a stamp you get with a purchase and save in special books until you have enough to take to a special store and trade for something you want. Mother always buys things in stores where they give trading stamps.
TRADING STAMP
Meaning of TRADING STAMP in English
American idioms English vocabulary. Английский словарь американских идиом. 2012