Rough spot where rat's tail should be (5)
I believe the answer is:
raspy
'rough' is the definition.
(I know that rough can be written as raspy)
'spot where rat's tail should be' is the wordplay.
I cannot really see how this works, but
'spot' could be 'spy' (synonyms) and 'spy' is present in the answer.
The remaining letters 'ra' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for raspy that I've seen is " Harsh, grating".)