Mistake in fling resulting in drink (6)
I believe the answer is:
sherry
'drink' is the definition.
(sherry is a kind of drink)
'mistake in fling' is the wordplay.
'mistake' becomes 'err' (to err is to make a mistake or blunder).
'in' indicates putting letters inside.
'fling' becomes 'shy' (shy can mean to throw).
'err' inserted inside 'shy' is 'SHERRY'.
'resulting in' is the link.
(Other definitions for sherry that I've seen before include "Fortified wine from Jerez" , "Alcoholic drink" , "Alcohol for the trifle" , "Strong sweet wine as aperitif" , "Jerez drink" .)