Coarse modification of nice detail (10)
I believe the answer is:
indelicate
'coarse' is the definition.
(I've seen this before)
'modification of nice detail' is the wordplay.
'modification of' indicates an anagram (I've seen 'modification' mean this).
'nice'+'detail'='nicedetail'
'nicedetail' with letters rearranged gives 'INDELICATE'.
(Other definitions for indelicate that I've seen before include "Rather rude" , "lacking taste" , "Rude - tasteless" , "Practised (a play)" , "Saucy" .)