Dim to confine two dukes in row (6)
I believe the answer is:
paddle
'row' is the definition.
(I've seen this in another clue)
'dim to confine two dukes' is the wordplay.
'two dukes' means two substitutions for 'duke'.
'dim' becomes 'pale' (I've seen this in another clue).
'to confine' is an insertion indicator.
'duke' becomes 'd' (abbreviation).
'duke' becomes 'd' (abbreviation).
'd'+'d'='dd'
'pale' placed around 'dd' is 'PADDLE'.
'in' is the link.
(Other definitions for paddle that I've seen before include "Short light oar" , "To move canoe, you have to" , "Small oar to propel canoe" , "Blade of a water wheel" , "Small propeller for canoe" .)