rubber stamp

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A piece of rubber affixed to a handle and bearing raised characters used to make ink impressions, as of names or dates.
2. n. A person or body that gives perfunctory approval or endorsement of a policy without assessing its merit.
3. n. A perfunctory approval or endorsement.

Wiktionary

1. adj. figuratively Of a person, organisation, or process, making decisions or approving matters routinely or without real power, as rubber stamp politics, a rubber stamp committee.
2. n. 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.
3. n. figuratively A person or organisation who approves, routinely or as a formality, matters decided by some other person or organisation.
4. v. colloquial to process, approve or decide matters routinely rather than through careful consideration

WordNet 3.0

1. n. a stamp (usually made of rubber) for imprinting a mark or design by hand
2. n. routine authorization of an action without questions