Get rid of cherubic child without father and identity (3,4,2)
I believe the answer is:
put paid to
'get rid of' is the definition.
(thesaurus)
'cherubic child without father and identity' is the wordplay.
'cherubic child' becomes 'putto' (term for an angelic child in Renaissance art).
'without' indicates putting letters inside ('without' can be similar in meaning to 'outside').
'father' becomes 'pa' (pa can mean dad or father).
'and' says to put letters next to each other.
'identity' becomes 'id' (I've seen this in other clues).
'pa'+'id'='paid'
'putto' going around 'paid' is 'PUT PAID TO'.
(Other definitions for put paid to that I've seen before include "Finish off, terminate - or issue receipt?" , "Destroy hopes or chances - send receipt?" , "Finish, destroy" , "Stop" , "End - destroy" .)