Metal container for my French energy drink? (8)
I believe the answer is:
lemonade
'drink?' is the definition.
(lemonade is a kind of drink)
'metal container for my french energy' is the wordplay.
'metal' becomes 'lead' (lead is a kind of metal).
'container for' indicates putting letters inside.
'my french' becomes 'mon' ('my' in French).
'energy' becomes 'e' (physics symbol as in E=mce).
'lead' enclosing 'mon' is 'lemonad'.
'lemonad'+'e'='LEMONADE'
(Other definitions for lemonade that I've seen before include "it refreshes" , "Non-alcoholic drink" , "(Usually) fizzy drink" , "Fizzy pop" , "Sweet carbonated drink" .)