1. (verb)jail, jailhouse, gaol, clink, slammer, poky, pokey a correctional institution used to detain persons who are in the lawful custody of the government (either accused persons awaiting trial or convicted persons serving a sentence)
2. (verb)imprison, incarcerate, lag, immure, put behind bars, jail, jug, gaol, put away, remand lock up or confine, in or as in a jail "The suspects were imprisoned without trial"; "the murderer was incarcerated for the rest of his life"
Definition of 'JAIL' 
