Eat in the evening (3)
I believe the answer is:
sup
'eat in the evening' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sup that I've seen before include "Eat a late meal; sip" , "A mouthful of liquid" , "Drink; take an evening meal" , "Drink; take a late meal" , "Drink -- eat (with the devil?)" .)