Such friends will always give you a drink (5)
I believe the answer is:
stout
'a drink' is the definition.
(stout is a kind of drink)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for stout that I've seen before include "Overweight; porter" , "tipple" , "Dark beer for the rather fat" , "Inured to fatigue and hardship" , "Rather fat, drink" .)