chelīdonius, a, um, adj., = χελιδόνιος, pertaining to the swallow: lapilli, found in the crop of young swallows, swallow-stone, Plin. 11, 37, 79, § 203: ficus, a particular reddish species of fig, Col. 10, 415; Plin. 15, 18, 19, § 71: gemma, Plin. 37, 10, 56, § 154.

— Subst.: chelīdonia, ae, f. (sc. herba): Chelidonium majus, Linn.; swallowwort, celandine, Plin. 25, 8, 50, §§ 89 and 90; also herba chelidoniae in Ser. Samm. 37, 699.