a. [ L. Castalius ] Of or pertaining to Castalia, a mythical fountain of inspiration on Mt. Parnassus sacred to the Muses. Milton. [ 1913 Webster ]

‖n. [ L., a chestnut, fr. Gr. &unr_;. ] (Bot.) A genus of nut-bearing trees or shrubs including the chestnut and chinquapin. [ 1913 Webster ]

n. See Castanets. [ 1913 Webster ]

n. pl. [ F. castagnettes, Sp. castañetas, fr. L. castanea (Sp. castaña) a chestnut. So named from the resemblance to two chestnuts, or because chestnuts were first used for castanets. See Chestnut. ] Two small, concave shells of ivory or hard wood, shaped like spoons, fastened to the thumb, and beaten together with the middle finger; -- used by the Spaniards and Moors as an accompaniment to their dance and guitars. [ 1913 Webster ]

☞ The singular, castanet, is used of one of the pair, or, sometimes, of the pair forming the instrument. [ 1913 Webster ]

The dancer, holding a castanet in each hand, rattles them to the motion of his feet. Moore (Encyc. of Music). [ 1913 Webster ]

n. a genus of evergreen trees and shrubs of warm regions valued for their foliage; found in southeastern U.S. and eastern Australia and northern New Zealand.
Syn. -- genus Castanopsis. [ WordNet 1.5 ]

n. 1. a genus consisting of one species, the Moreton Bay chestnut.
Syn. -- genus Castanospermum. [ WordNet 1.5 ]

n. 1. One who, or that which, is cast away or shipwrecked. [ 1913 Webster ]

2. One who is ruined; one who has made moral shipwreck; a reprobate. [ 1913 Webster ]

Lest . . . when I have preached to others, I myself should be a castaway. 1 Cor. ix. 27. [ 1913 Webster ]

a. Of no value; rejected; useless. [ 1913 Webster ]