castling UK /ˈkɑːstlɪŋ/US /ˈkæstlɪŋ/noun 4/ˈkæsəlɪŋ/ noun 2forms 1 noun4 •One that is cast. •A miniature cast or mould. •(no longer used) An abortion, or a premature birth.1646: Wherein notwithstanding, we should rather rely upon the urine in a castling’s bladder — Sir Thomas Browne, Pseudodoxia Epidemica, Book II, ch 5 — 1646 •(no longer used) The second or third swarm of bees which leaves a hive in a season. castling UK /ˈkɑːsəlɪŋ/US /ˈkæsəlɪŋ/ noun2 •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.Castling is prevented temporarily: […] If there is any piece between the king and the rook with which castling is to be effected. — 2022 •The act of constructing a defense structure in Japanese chess in which the king (玉) is positioned in a certain way so that it is protected by pawns (歩) and silver general(s) (銀) and/or gold general(s) (金) often with an additional knight (桂) and lance (香車). formscastlings