Stay till the end of something dull
Occupy a building to protest about something
Be on a committee
To handle somebody firmly who behaves impertinently, conceitedly
Hold information back or keep it secret
Wait for something to happen without making any effort
Relax in a chair
Take on someone's responsibilities while they are absent
Pose for an artist or photographer
Look after children while their parents are out
Sit and do nothing, especially when you should be working
Not try to stop something
Reconcile different positions
Alternative spelling of sit-up; Alternative spelling of situp