From Longman Dictionary of Contemporary Englishjailerjail‧er (also gaoler British English) /ˈdʒeɪlə $ -ər/ noun [countable] old-fashioned PRISONsomeone who is in charge of guarding a prison or prisoners
Examples from the Corpus
jailer• Typically the victim is a woman who has been assaulted by a jailer or police officer.• But through the news media, Arpaio has managed to recast the image of county jailer into that of Wild West sheriff.• It was officially said that he had intimidated his helot jailer into giving him the knife, and had so mangled himself.• A lonely jailer places desperate advertisements for a wife.• The provodnik, my jailer, showed a young bearded man into my compartment.• He is not only a prisoner but is conditioned to be his own jailer too. 