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' is hidden in the letters of '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" .)