Particular, unique (7)
I believe the answer is:
special
This clue is a double definition.
'particular' is the first definition.
(I know that particular can be written as special)
'unique' is the second definition.
(I've seen this in another clue)
(Other definitions for special that I've seen before include "Important; particular" , "Dish not on main menu" , "Different from usual" , "Particular, distinctive" , "Day's non-menu dish" .)