Custodian or steward (6)
I believe the answer is:
keeper
I believe this is a double definition.
'custodian' is the first definition.
(I know that custodian can be written as keeper)
'steward' is the second definition.
(I know that steward can be written as keeper)
(Other definitions for keeper that I've seen before include "slips on my right hand usually" , "Guardian, in the zoo say" , "Cain asked 'Am I my brother's ......?'" , "Reluctant" , "Zoo attendant" .)