Take Robert back with argument (6)
I believe the answer is:
borrow
'take' is the definition.
(I know that borrow is a more specific form of the action take)
'robert back with argument' is the wordplay.
'robert' becomes 'rob' (short for Robert).
'back' shows that the letters should be reversed in order.
'with' says to put letters next to each other.
'argument' becomes 'row' (to row is to argue).
'rob' written backwards gives 'bor'.
'bor'+'row'='BORROW'
(Other definitions for borrow that I've seen before include "Take on loan" , "Temporarily adopt" , "Get the temporary use of, but give back" , "Beg, ...... or steal - get at all costs" , "Receive as a loan" .)