Drink is evil? Not very when taken with old American marijuana (3,3)
I believe the answer is:
ice tea
'drink' is the definition.
(ice tea is a kind of drink)
'evil? not very when taken with old american marijuana' is the wordplay.
'evil? not very when taken with old american' becomes 'ice' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'marijuana' becomes 'tea' (slang term for the drug).
'ice'+'tea'='ICE TEA'
'is' is the link.
Can you help me to learn more?
(Other definitions for ice tea that I've seen before include "Chilled drink flavoured with lemon" , "refresher" , "Cold summer drink" , "refreshing drink" , "Cool non-alcoholic drink" .)