sit in (v.)

• ball
• beef
• bitch
• boggle
• boycott
• brawl
• caucus
• challenge
• commission
• complain
• contribute
• dance
• date
• demonstrate
• demur
• diet
• dispute
• exception
• expostulate
• fete
• holler
• howl
• join
• kick
• march
• meet
• object
• panel
• partake
• participate
• party
• picket
• protest
• rally
• remonstrate
• rendezvous
• scruple
• squawk
• strike
• vote