A piece of rubber or similar material with a design or text carved or molded for the purpose of transferring ink or dye to imprint that design on another object.

“The library had a rubber stamp to imprint the due date.”

A person or organisation that approves, routinely or as a formality, matters decided by some other person or organisation.

To process, approve or decide matters routinely rather than through careful consideration.

“They usually just rubber stamp orders under $100.”

Of a person, organisation, or process, making decisions or approving matters routinely or without real power.

“rubber stamp committee”