Drink for American; two litres is nothing (3,3)
I believe the answer is:
sod all
'is nothing' is the definition.
(I've seen this before)
'drink for american two litres' is the wordplay.
I cannot quite understand how this works, but
'drink' could be 'soda' (soda is a kind of drink) and 'soda' is found in the answer.
'litres' could be 'll' (the abbreviation for litre written twice) and 'll' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sod all that I've seen before include "nothing" , "duck, perhaps?" .)