Potty rough, nipper's rear pulled out (4)
I believe the answer is:
daft
'potty' is the definition.
(I've seen this before)
'rough nipper's rear pulled out' is the wordplay.
I cannot quite see how this works, but
'rear' could be 'aft' (I've seen this in another clue) and 'aft' is found in the answer.
A single letter 'd' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for daft that I've seen before include "Informally silly or crazy" , "Half-witted" , "Potty" , "Bats!" , "Idiotic" .)