Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† cīris, is, f., = κεῖρις, a bird (acc. to Hyg. Fab. 198, a fish = κίρρις, Etym. M.), into which Scylla, the daughter of Nisus, was changed, Ov. M. 8, 151; Verg. Cir. 488 sq.