Hand on new piece (4)
I believe the answer is:
pawn
'hand' is the definition.
(I know that pawn is a more specific form of the action charge)
'on new piece' is the wordplay.
'on' is a charade indicator (letters next to each other).
'new' becomes 'n' (abbreviation as in New Testament NT).
'piece' becomes 'paw' (paw is a kind of piece).
'n' put after 'paw' is 'PAWN'.
(Other definitions for pawn that I've seen before include "Get ready for" , "Give as security" , "Deposit as pledge" , "The foot-soldier in chess" , "one used by another" .)