Each new part epic with article (3,6)
I believe the answer is:
per capita
'each' is the definition.
(thesaurus)
'new part epic with article' is the wordplay.
'new' indicates anagramming the letters.
'with' is an insertion indicator.
'article' becomes 'a' (indefinite article).
'part'+'epic'='partepic'
'partepic' with letters rearranged gives 'percpita'.
'percpita' enclosing 'a' is 'PER CAPITA'.
(Other definitions for per capita that I've seen before include "A head" , "apiece" , "For each person - in routine Latin phrase" .)