Drink from a plastic cup? (4)
I believe the answer is:
asti
'drink' is the definition.
(Asti is a type of wine)
'from a plastic cup?' is the wordplay.
'from' indicates the answer is hidden within the clue.
'ASTI' is hidden within 'plastic cup'.
(Other definitions for asti that I've seen before include "It's a (anag) - wine" , "Italian white wine" , "Piedmontese white wine" , "Sparkling wine named after an Italian Piedmont town" , "Italian town, famous for its wine" .)