Move permitting movement of two pieces in single move on chessboard? (8)
I believe the answer is:
castling
'move' is the definition.
(castling is a kind of move)
'move on chessboard?' is the wordplay.
'move' becomes 'cast' (casting is a kind of moving).
'on chessboard?' becomes 'ling' (I am not sure about this - if you are sure you should believe this answer much more).
'cast'+'ling'='CASTLING'
'permitting movement of two pieces in single' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for castling that I've seen before include "Moving two men on board" , "defence of the board" , "chess move" .)