It's mean to criticise (3,2)
I believe the answer is:
get at
I believe this is a double definition.
'it's mean to' is the first definition.
(I've seen this before)
'criticise' is the second definition.
(I've seen this before)
(Other definitions for get at that I've seen before include "Criticise (someone)" , "Unfairly influence" , "Intend" , "Reach - mean - attack verbally" , "Pick on - gain access to" .)