A small adhesive piece of paper used to show that postage for a letter has been paid.

“Don't forget to put a stamp on the envelope before mailing it.”

An instrument or device for engraving, printing, or embossing a design or mark.

“The officer put a red stamp in my passport at the border.”

To bring down one's foot heavily on the ground or on something.

“The little boy began to stamp his feet when he didn't get his way.”