sit on

verb sits on · sitting on · sat on · sit upon

1. idiomatic, transitive To block, suppress, restrain (something). The chairman sat on the report until the end of the legislative session.
2. idiomatic, informal, transitive To restrain (a person). He started to act up, but she sat on him.
3. idiomatic, transitive To take no action on (something); to hold (something) in reserve without actually using. I sent the boss my proposal three weeks ago and he's just been sitting on it.
4. transitive To be a member of (something). He sits on the appropriations committee.
5. transitive To hold an official inquiry regarding (something); to deliberate about (something).
6. euphemistic, transitive To insert (something) into one's vagina or anus from below. Let me sit on it.
7. transitive Used other than figuratively or idiomatically: see sit, on. The cat sat on the mat.