The two litres consumed in rounds in play (7)
I believe the answer is:
othello
'play' is the definition.
(I've seen this before)
'the two litres consumed in rounds' is the wordplay.
'two litres' can mean two replacements for 'litre'.
'litre' becomes 'L' (abbreviation).
'litre' becomes 'L' (abbreviation).
'consumed in' means one lot of letters goes inside another.
'rounds' becomes 'oo' (two O's - O is a round letter).
'the'+'l'+'l'='thell'
'thell' put within 'oo' is 'OTHELLO'.
'in' is the link.
(Other definitions for othello that I've seen before include "Shakespearean hero" , "Hello to Shakespeare's tragic hero" , "Literary character" , "Jealous character" , "He murdered his wife Desdemona" .)