He'll never do well in civic administration (3)
I believe the answer is:
cad
'he'll never do well' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'in civic administration' is the wordplay.
'in' indicates a hidden word.
'CAD' can be found hidden inside 'civic administration'.
Can you help me to learn more?
(Other definitions for cad that I've seen before include "A knave, real rotter" , "he's no gent" , "Blackguard" , "Rotter, bounder" , "That ain't no gentleman" .)