Edging of garter that hurts curmudgeon (6)
I believe the answer is:
grouch
'curmudgeon' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'edging of garter that hurts' is the wordplay.
'edging of garter' becomes 'gr' (I can't explain this - if you can you should give a lot more credence to this answer).
'that hurts' becomes 'ouch'.
'gr'+'ouch'='GROUCH'
Can you help me to learn more?
(Other definitions for grouch that I've seen before include "Complaint" , "Grumble - complain" , "Bad-tempered person" , "one known for grumbling" , "Bad-tempered complainant" .)