postage stamp

noun

small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage

A small piece of printed paper stuck on an item to be mailed, indicating that postage has been paid.
“The postage stamps on the letters from overseas were almost as interesting as the letters themselves.”
A very small area.
“We have just a postage stamp of a back garden.”
The upper left- or right-hand corner of the goal.
“[…] got in on the act himself, firing in an unstoppable shot that arced into the postage stamp top corner of Andy Goram's goal.”