Not representative or usual (8)
I believe the answer is:
atypical
'not representative or usual' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for atypical that I've seen before include "Deviating from what is usual or common" , "Unusual" , "'Abnormal, aberrant (8)'" , "Not conforming to a norm or average" , "Abnormal, aberrent." .)