You could drink to such friends (5)
I believe the answer is:
stout
'to such friends' is the definition.
I can't judge whether this definition defines the answer.
'you could drink' is the wordplay.
'you' becomes 'u' (homophones).
'could' becomes 'stot' (I can't justify this - if you can you should give a lot more credence to this answer).
'drink' means one lot of letters goes inside another.
'u' put inside 'stot' is 'STOUT'.
Can you help me to learn more?
(Other definitions for stout that I've seen before include "Portly or stalwart" , "Thick; beer" , "of above-average weight" , "Fat; dependable" , "Kind of beer" .)