Synonyms for Prison:

n.

boot camp, concentration camp, death camp, correctional facility, camp, detention center. correctional, internment, hoosegow, big house, life imprisonment, life, life sentence, hard labor, pokey, free, house of correction, extraordinary rendition, stir, Calaboose, slammer, clink, can. artifact (noun)
prison house.
enclosure (noun)
confinement, enclosure, barrier, trap, envelopment.
penal institution (noun)
penal colony, big house.
penitentiary (noun)
guardhouse, Panopticon.
pokey (noun)
pokey.
prison (noun)
dungeon, cell, bridle, jailhouse, pillory, irons, brig, prison house, manacle, straight jacket, pen, penitentiary, pinion, reformatory, Alcatraz, fence, tether, shackle, San Quentin, lockup, reform school, confine, jail, handcuff, stockade, pound, penal colony, coop, harness, jug, vise, bastille, keep, cage, gaol, stronghold, oubliette, cooler, collar.
punishment device (noun)
whipping post, torture chamber, cowhide, rack, bull whip, birch rod, captivity, whip, rod, strap, block, guillotine, stocks, noose, cane, electric chair, solitary confinement, thumbscrew, rawhide, gibbet, gas chamber, thong, ax, rope, scaffold, switch, truncheon, maiden, stake, iron, gallows, lash.
residence for incarcerating criminals (noun)
confinement, keep, bastille, clink, reformatory, guardhouse, penitentiary, pen, jail, cooler, lockup, can, stockade, slammer, dungeon.

Other synonyms:

house of correction, hoosegow, hard labor, life sentence, extraordinary rendition, big house, correctional, Calaboose, life imprisonment, slammer, pokey. clink. life. jail
can.
Other relevant words:
correctional, hoosegow, guardhouse, stir, prison house, slammer, pokey, clink, Calaboose, big house, concentration camp, house of correction, can, Panopticon.

Usage examples for prison

  1. She was in prison herself, poor woman. – The Delectable Duchy by Arthur Thomas Quiller-Couch
  2. " Go to Sing Sing prison – Edgar Saltus: The Man by Marie Saltus