A fattening drink? (5)
I believe the answer is:
stout
'drink?' is the definition.
(type of beer)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for stout that I've seen before include "Strong; drink" , "Robust; drink" , "Kind of beer" , "tipple" , "Fat; dependable" .)