Overturning alcoholic drink is mistake (4)
I believe the answer is:
slip
'is mistake' is the definition.
(a slip is a blunder or mistake)
'overturning alcoholic drink' is the wordplay.
'overturning' says the letters should be written in reverse.
'alcoholic drink' becomes 'pils' (short for Pilsner).
'pils' written backwards gives 'SLIP'.
(Other definitions for slip that I've seen before include "Mistake (of tongue or pen)" , "Clay, water mix; fielder" , "Nod" , "Careless mistake" , "Glide; petticoat" .)