[ˈkɑːsl], (Noun)

Definitions:
- a large building, typically of the medieval period, fortified against attack with thick walls, battlements, towers, and in many cases a moat
(e.g: Edinburgh Castle)


Phrases:
- castles in the air

Origin:
late Old English castel: from Anglo-Norman French and Old Northern French castel, from Latin castellum, diminutive of castrum ‘fort’

[ˈkɑːsl], (Verb)

Definitions:
- make a special move (no more than once in a game by each player) in which the king is transferred from its original square two squares along the back rank towards a rook on its corner square which is then transferred to the square passed over by the king
(e.g: both of the players castled on the queenside)


Phrases:
- castles in the air

Origin:
late Old English castel: from Anglo-Norman French and Old Northern French castel, from Latin castellum, diminutive of castrum ‘fort’