Incorporate half of them with main part (6)
I believe the answer is:
embody
'incorporate' is the definition.
(thesaurus)
'half of them with main part' is the wordplay.
'half of' indicates taking half.
'with' says to put letters next to each other.
'main part' becomes 'body' (I've seen this before).
'them' halved is 'em'.
'em'+'body'='EMBODY'
(Other definitions for embody that I've seen before include "Incorporate, represent" , "Incorporate or express in visible form" , "Express concretely - personify" , "Express, say ideas, in visible form" , "Contain within oneself, incorporate" .)