Unusual; eccentric (8)
I believe the answer is:
singular
This clue is a double definition.
'unusual' is the first definition.
(I've seen this before)
'eccentric' is the second definition.
(thesaurus)
(Other definitions for singular that I've seen before include "Extraordinary, with reference to one" , "Unusual, maybe unique" , "Gnu's lair (anag.)" , "Unusual, striking, or unique" , "As sheep may be, but not cattle or horses" .)