Clothes making Martine look fancy (7)
I believe the answer is:
raiment
'clothes' is the definition.
(raiment is a kind of clothes)
'martine look fancy' is the wordplay.
'look fancy' indicates an anagram (fancy suggests something unusual or different).
'martine' is an anagram of 'RAIMENT'.
'making' acts as a link.
(Other definitions for raiment that I've seen before include "Am inert (anag) - clothing" , "Apparel" , "Poetic word for clothing" , "Especially fine or decorative clothing" , "Garment" .)