Strange characteristic (8)
I believe the answer is:
peculiar
I believe this clue is a double definition.
'strange' is the first definition.
('peculiar' can be a synonym of 'strange')
'characteristic' is the second definition.
(I've seen this before)
(Other definitions for peculiar that I've seen before include "I clear up, being odd" , "Odd, rum, funny" , "'Strange, odd (8)'" , "sick" , "Strange, I clear up" .)