Entry 2 senses · 2 variants Webster, 1913 Castling · Cast·ling · IPA /ˈkæstlɪŋ/ n. n. 01 n. That which is cast or brought forth prematurely; an abortion. 1. That which is cast or brought forth prematurely; an abortion. 02 n. A compound move of the king and castle. See Castle, v. i. 1. A compound move of the king and castle. See Castle, v. i.(Chess) See: Castle