Chess player's move in splendid house (6)
I believe the answer is:
castle
I believe this clue is a triple definition!
'chess player's' is the first definition.
(castle is a kind of chess piece)
'move' is the second definition.
(castle is a kind of move)
'in' acts as a link.
'splendid house' is the third definition.
(I've seen this before)
(Other definitions for castle that I've seen before include "E.g. Harlech, Beaumaris, Windsor" , "''An Englishman's home is his . . .''" , "Large building; rook" , "Let sac be a chess piece" , "fortification" .)