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