The headword, extracted from the quotation given, is the accusative singular of the third-declension feminine noun kre/c, h(, kreko/s; cf. LSJ s.v. (and Hesychius kappa4052).
[1] From Callimachus, Hecale fr. 288 Pfeiffer (82 Kapp, 39 Schneider). Scylla -- nothing to do with sigma 709 -- was the daughter of the legendary King Nisus (OCD(4) s.v.) of Megara (Barrington Atlas map 58 grid E2), of which Nisaia is the harbor district (cf. nu 422, nu 423, and nu 424). When the Cretan King Minos (cf. mu 1092 and OCD(4) s.v.) laid siege to Megara, Scylla cut the tuft of hair upon which her father relied for his power and the security of his city.