Blow over pop off having drink (3,4)
I believe the answer is:
die down
'blow over' is the definition.
'pop off having drink' is the wordplay.
'pop off' becomes 'die'.
'having' means one lot of letters go next to another.
'drink' becomes 'down' (downing is a kind of drinking**).
'die'+'down'='DIE DOWN'
(Other definitions for die down that I've seen before include "Become less intense" , "Quieten" , "get quiet" , "For ease" , "fade" .)