Jailer (7)
'jailer' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for warder that I've seen before include "One is in charge of prisoners" , "Reward for prison guard" , "keeper" , "Gaoler" , "Jailer" .)
'jailer' is the definition.
(I know that jailer can be written as turnkey)
This is the entire clue.
(Other definitions for turnkey that I've seen before include "Designed and ready for immediate use by the purchaser" , "Jailer (archaic), (of service) provided ready for use" , "ready to start working immediately" , "Warder banging up" , "Old jailer" .)