The Collaborative International Dictionary of English v.0.48:
Jailer \Jail"er\, n. [OE. jailer, gailer, OF. geolier, F. ge[^o]lier. See Jail.] The keeper of a jail or prison. [Written also jailor, gaoler.]WordNet (r) 3.0 (2006):
jailor n 1: someone who guards prisoners [syn: prison guard, jailer, jailor, gaoler, screw, turnkey]