Coat in shop -- it is unusual in style (14)
I believe the answer is:
sophistication
'style' is the definition.
(thesaurus)
'coat in shop it is unusual' is the wordplay.
'unusual' is an anagram indicator.
'coat'+'in'+'shop'+'it'+'is'='coatinshopitis'
'coatinshopitis' with letters rearranged gives 'SOPHISTICATION'.
'in' acts as a link.
(Other definitions for sophistication that I've seen before include "Polish" , "Fashionable refinement" .)