Evil family are absorbed (4,2)
I believe the answer is:
sink in
'are absorbed' is the definition.
'evil family' is the wordplay.
'evil' becomes 'sin' (I've seen this before).
'family' becomes 'kin' ('kin' can be a synonym of 'family').
'sin'+'kin'='SINK IN'
(Other definitions for sink in that I've seen before include "(Of facts) become fully understood" , "Penetrate, become understood" , "Get through" , "Be absorbed" , "Register" .)