Best hand in baccarat (4)
I believe the answer is:
nine
'best hand in baccarat' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nine that I've seen before include "SECOND PART OF 14" , "Number IX" , "Square next up after four" , "One over the eight" , "Days Lady Jane 5 ac reigned" .)