Uncommon in Ankara restaurants (4)
I believe the answer is:
rare
'uncommon' is the definition.
('rare' can be similar in meaning to 'uncommon')
'in ankara restaurants' is the wordplay.
'in' indicates a hidden word.
'RARE' is hidden in the letters of 'ankara restaurants'.
(Other definitions for rare that I've seen before include "Unusual - exquisite" , "not often spotted" , "'Unusual, uncommon (4)'" , "like Ben Jonson, Jack Young thought" , "not dense" .)