Criticise second drink (5,4)
I believe the answer is:
knock back
'drink' is the definition.
(thesaurus)
'criticise second' is the wordplay.
'criticise' becomes 'knock' (I've seen this before).
'second' becomes 'back' (to second a motion is to back it).
'knock'+'back'='KNOCK BACK'
(Other definitions for knock back that I've seen before include "finish off drink quickly" , "Refuse" , "Disappointing rejection" , "Turn down - drink" , "Refusal" .)