Hand on new hock (4)
I believe the answer is:
pawn
'hock' is the definition.
('pawn' can be a synonym of 'hock')
'hand on new' is the wordplay.
'hand' becomes 'paw' ('paw' can be a synonym of 'hand').
'on' says to put letters next to each other.
'new' becomes 'n'.
'paw'+'n'='PAWN'
(Other definitions for pawn that I've seen before include "Person one used" , "Chesspiece" , "Hock; cat's-paw" , "Minor chessman" , "Stooge; hock" .)