What is the meaning of Sit_on?

To block, suppress, restrain (something).

To restrain (a person).

To take no action on (something); to hold (something) in reserve without actually using.

To be a member of (something).

To hold an official inquiry regarding (something); to deliberate about (something).

To insert (something) into one's vagina or anus from below.

Used other than figuratively or idiomatically: see sit, on.

Source: wiktionary.org