He has minor responsibilities (8)
I believe the answer is:
guardian
'he has minor responsibilities' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he' is the wordplay.
I cannot really see how this works, but
'he' could be 'ian' and 'ian' is found in the answer.
The remaining letters 'guard' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for guardian that I've seen before include "Type of angel" , "Protector, keeper" , "Argus" , "Champion - paper" , "Curator" .)