Shockingly unusual (5)
I believe the answer is:
outre
'shockingly unusual' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for outre that I've seen before include "Odd, bizarre" , "Deviating from normal" , "flamboyant" , "Eccentric or unseemly - in France" , "Bizarre or eccentric in France" .)