Noblewoman and duke united by board game (7)
I believe the answer is:
duchess
'noblewoman' is the definition.
(I know that duchess is a type of noblewoman)
'duke united by board game' is the wordplay.
'duke' becomes 'd' (abbreviation).
'united' becomes 'U' (abbreviation).
'by' means one lot of letters go next to another.
'board game' becomes 'chess' (chess is a kind of board game).
'd'+'u'+'chess'='DUCHESS'
'and' acts as a link.
(Other definitions for duchess that I've seen before include "Female aristocrat" , "Noble lady" , "Titled female" , "title" , "Titled lady" .)