Odd or unconventional (9)
I believe the answer is:
eccentric
This clue is a double definition.
'odd' is the first definition.
(both can mean unusual)
'unconventional' is the second definition.
(similar in meaning)
(Other definitions for eccentric that I've seen before include "Wacky" , "Somewhat peculiar" , "character" , "Unconventionally strange" , "Odd or uncoventional in manner or appearance" .)