Gosh! A mug for the drink! (7)
I believe the answer is:
cordial
'the drink' is the definition.
(cordial is a kind of drink)
'gosh a mug' is the wordplay.
'gosh' becomes 'cor' (I've seen this before).
'a mug' becomes 'dial' (both can mean one's face).
'cor'+'dial'='CORDIAL'
'for' acts as a link.
(Other definitions for cordial that I've seen before include "stimulating drink" , "Warm and friendly; drink" , "Hearty, affectionate" , "Pleasant - soft drink" , "Agreeable - drink" .)