gaoler(n = noun.person) jailer, jailor, prison guard, screw, turnkey - someone who guards prisoners;
is a kind of keeper, law officer, lawman, peace officer
Derived form verb gaol₁

   The keeper of a jail. Same as Jailer. [1913 Webster]

gaoler, Brit. var. of JAILER.

N  keeper, custodian, custos, ranger, warder, jailer, gaoler, turnkey, castellan, guard, watchdog, watchman, Charley, chokidar, durwan, hayward, sentry, sentinel, watch and ward, concierge, coast guard, guarda costa, game keeper, escort, bodyguard, protector, governor, duenna, guardian, governess, nurse, nanny, babysitter, catsitter, dogsitter, bonne, ayah.