He does nothing to express his grievances (7)
I believe the answer is:
striker
'nothing to express his grievances' 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 'rik' and 'rik' is found within the answer.
The remaining letters 'ster' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'does' is the link.
Can you help me to learn more?
(Other definitions for striker that I've seen before include "A forward on a soccer team" , "Soccer player whose main function is to score goals" , "disaffected employee" , "Football attacker" , "he's still batting" .)