One of a kind (4)
'one of a kind' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for unique that I've seen before include "Singular, different from others" , "incomparable" , "Sole" , "Singular, not like any other" , "Singular, without equal" .)
'one of a kind' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for unit that I've seen before include "Part of a kit" , "Single person - group of people" , "- - trust" , "Separate part" , "Mexican maize pancake" .)