Hands should accept northern men on board (5)
I believe the answer is:
pawns
'men on board' is the definition.
(I've seen this before)
'hands should accept northern' is the wordplay.
'hands' becomes 'paws' ('paw' can be a synonym of 'hand').
'should accept' is an insertion indicator.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'paws' going around 'n' is 'PAWNS'.
(Other definitions for pawns that I've seen before include "made pledges" , "The foot-soldiers in chess" , "Puts into hock" , "Chess pieces" , "Minor chessmen" .)