Black in Kentucky (4)
I believe the answer is:
inky
'black' is the definition.
('inky' can be similar in meaning to 'black')
'in kentucky' is the wordplay.
'kentucky' becomes 'ky'.
'in'+'ky'='INKY'
(Other definitions for inky that I've seen before include "Like writing fluid" , "Black; drunk (Aus. sl.)" , "Completely dark" , "Leaked on by pen" , "Dark; stained" .)