Custodian appeal aliens back (7)
I believe the answer is:
steward
'custodian' is the definition.
(I know that custodian can be written as steward)
'appeal aliens back' is the wordplay.
'appeal' becomes 'draw' (draw can mean appeal or attraction).
'aliens' becomes 'ETs' (ET is short for extraterrestrial).
'back' says the letters should be written backwards.
'draw'+'ets'='drawets'
'drawets' written backwards gives 'STEWARD'.
(Other definitions for steward that I've seen before include "Waiter; estate manager" , "College caterer" , "Shipboard attendant" , "Cabin attendant" , "Airline cabin worker" .)