Knickers don't abrade much (9)
I believe the answer is:
underwear
'much' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'knickers don't abrade' is the wordplay.
'knickers don't' becomes 'under' (I can't explain this - if you can you should give a lot more credence to this answer).
'abrade' becomes 'wear' (I've seen this in another clue).
'under'+'wear'='UNDERWEAR'
Can you help me to learn more?
(Other definitions for underwear that I've seen before include "slips, perhaps" , "Endure war about smalls" , "Garments worn next to the skin" , "Possibly slips" , "Nether garments" .)