1.  guardroom(n = noun.artifact) - a cell in which soldiers who are prisoners are confined;
is a kind of cell, jail cell, prison cell

2.  guardroom(n = noun.artifact) - a room used by soldiers on guard;
is a kind of room

   The room occupied by the guard during its term of duty; also, a room where prisoners are confined. [1913 Webster]

guardroom, n. a room with the same purpose as a guardhouse.

N  prison, prison house, jail, gaol, cage, coop, den, cell, stronghold, fortress, keep, donjon, dungeon, Bastille, oubliette, bridewell, house of correction, hulks, tollbooth, panopticon, penitentiary, guardroom, lockup, hold, round house, watch house, station house, sponging house, station, house of detention, black hole, pen, fold, pound, inclosure, isolation (exclusion), penal settlement, penal colony, bilboes, stocks, limbo, quod, calaboose, chauki, choky, thana, workhouse, Newgate, Fleet, Marshalsea, King's Bench, Queen's Bench, bond, bandage, irons, pinion, gyve, fetter, shackle, trammel, manacle, handcuff, straight jacket, strait jacket, strait-jacket, strait-waistcoat, hopples, vice, vise, yoke, collar, halter, harness, muzzle, gag, bit, brake, curb, snaffle, bridle, rein, reins, bearing rein, martingale, leading string, tether, picket, band, guy, chain, cord, cavesson, hackamore, headstall, jaquima, lines, ribbons, bolt, deadbolt, bar, lock, police lock, combination lock, padlock, rail, wall, stone wall, paling, palisade, fence, picket fence, barbed wire fence, Cyclone fence, stockade fence, chain-link fence, barrier, barricade, drag.