Unusually good (4)
'unusually good' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rare that I've seen before include "Unusual - exquisite" , "Very scarce, like undercooked steak" , "Exceptional" , "Unusual(ly fine)" , "Not often seen - underdone" .)
'unusually good' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for exceptional that I've seen before include "Outstanding; not typical" , "Out of the ordinary" , "Extraordinary!" , "Unusually good" , "Very unusual" .)