1.NounA 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."
2.NounA person or organization that approves, routinely or as a formality, matters decided by some other person or organization.
"During the Roman principate, the senate largely served as a rubber stamp for the emperor."
3.AdjectiveOf a person, organization, or process, making decisions or approving matters routinely or without real power.
"rubber stamp politics"
4.VerbTo process, approve or decide matters routinely rather than through careful consideration.
"They usually just rubber stamp orders under $100."