sit on
Pronunciation:
verb
Definitions
To block, suppress, restrain.
Example: The chairman sat on the report until the end of the legislative session.
To restrain (a person).
Example: He started to act up, but she sat on him.
To take no action on.
Example: I sent the boss my proposal three weeks ago and he's been just sitting on it.
To be a member of.
Example: He sits on the appropriations committee.