Old Bill in the part of Marco Polo (3)
I believe the answer is:
cop
'old bill' is the definition.
The definition and answer can be both to do with ownership as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'part of marco polo' is the wordplay.
'part of' indicates a hidden word.
'COP' can be found hidden inside 'marco polo'.
'in the' acts as a link.
Can you help me to learn more?
(Other definitions for cop that I've seen before include "Police officer (informal)" , "catch" , "Policeman (colloq.)" , "An American policeman" , "Policeman (sl)" .)