(chess) A move in which the king moves two squares towards a rook, and the rook moves to the other side of the king; the action of the verb to castle.

present participle of castle

plural of castling

A surname.

Synonym of bouncing castle

The first fast-food hamburger chain and one of the oldest American fast-food restaurant chains, known for its Slyder, a small square burger.

A nut with rounded extensions projecting past the nut's opening. A cotter pin is inserted through a hole in the bolt and bent around the castle nut's projections to lock the nut in place.

plural of castle nut

plural of castle in the air

(idiomatic) A desire, idea, or plan that is unlikely to ever be realized; a visionary project or scheme; a daydream, an idle fancy, a near impossibility.