lockup (n.)
- bastille
- borstal
- brig
- can
- cell
- check
- clink
- confinement
- constraint
- cooler
- coop
- gaol
- guardhouse
- hoosegow
- impoundment
- jail
- jailhouse
- jug
- keep
- oubliette
- pen
- penitentiary
- penning
- pokey
- prison
- reformatory
- restraint
- restriction
- stockade
- tollbooth