Elliptical character (9)
I believe the answer is:
eccentric
This clue is a double definition.
'elliptical' is the first definition.
(astronomical term)
'character' is the second definition.
(I know that character can be written as eccentric)
(Other definitions for eccentric that I've seen before include "Unconventional in appearance or behaviour" , "not moving in proper circles?" , "not precisely circular" , "Nut" , "Somewhat peculiar" .)