Violating convention (5)
I believe the answer is:
outre
'violating convention' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for outre that I've seen before include "Remarkable" , "Eccentric or unseemly kind of route" , "Disturbingly unusual" , "Extravagant - fantastic" , "Beyond the usual" .)