Case of dirty clothing isn't nice (6)
I believe the answer is:
dainty
'nice' is the definition.
(I know that nice can be written as dainty)
'case of dirty clothing isn't' is the wordplay.
'case of' suggests removing the centre (outsides of).
'clothing' means one lot of letters goes inside another (some letters cover up or clothe others).
'isn't' becomes 'aint' (non-standard version of 'isn't').
'dirty' with its centre taken out is 'dy'.
'dy' going around 'aint' is 'DAINTY'.
(Other definitions for dainty that I've seen before include "Piece of cake!" , "Small and pretty, delicate" , "Delicate, tasteful" , "Exquisite" , "Petite and elegant" .)