The headword, attested only in lexicography, is a masculine noun (connected with the verb phi 664) in the nominative singular; see generally LSJ s.v.
[1] The headword is identically glossed in Hesychius, Lexica Segueriana 411.25, the Synagoge, and Photius' Lexicon. [In her critical apparatus Adler reports that the corrected edition of ms M transmits the genitive katasko/pou.] For other entries with this gloss cf. epsilon 65, sigma 659, sigma 663, tau 423.