executioner
From Longman Dictionary of Contemporary Englishexecutionerex‧e‧cu‧tion‧er /ˌeksəˈkjuːʃənə $ -ər/ noun [countable] SCCKILLsomeone whose job is to execute criminalsExamples from the Corpusexecutioner• The baffled executioners were severely reprimanded before getting another crack at Vincent.• Prison officials drew less passionate executioners from a list of law-enforcement officers.• Drink was always a problem for some executioners, though it doubtless provided a blessed relief from their horrific duties.• Maskell came close to being the executioner.