Dines in great style (4)
I believe the answer is:
eats
'dines' is the definition.
(I've seen this before)
'in great style' is the wordplay.
'in' says the answer is hidden in the clue.
'EATS' is hidden within 'great style'.
(Other definitions for eats that I've seen before include "corrodes" , "snacks" , "Scoff" , "Consumes with teas" , "Swallows food" .)