Uncommon, rare (7)
I believe the answer is:
unusual
This clue is a double definition.
'uncommon' is the first definition.
(similar in meaning)
'rare' is the second definition.
(I've seen this before)
(Other definitions for unusual that I've seen before include "Not common or ordinary" , "Odd - rare" , "Infrequent" , "Anything but common." , "Not normal, strange" .)