lock-in

noun

ˈläk-ˌin 

plural lock-ins

1

: a demonstration in which protestors lock themselves inside a building, factory, etc.

When those demands weren't met, students took over several school buildings and began a lock-in on March 11.

—P. R. Lockhart

2

: a usually supervised social event for young people confined to a space (such as a library or church) often overnight

Each year, students are enticed to participate in a post-prom lock-in with the promise of games, prizes, food and fun.

—Jasmine Dent Franks

Christian youth lock-ins aren't unusual in religious Texas, though they usually happen in churches. Every so often, a church group will leave a house of worship and rent out a mall or skating rink after normal operating hours.

—Steve Jansen

Word History

First Known Use

1920, in the meaning defined at sense 1