The headword (for which cf. kappa 1877), a feminine noun, is the Attic form of epic kni/sh; see LSJ s.v. Its appearance here in the nominative singular makes its source hard to identify; perhaps Aristophanes, Birds 1517, though it could simply be paradigmatic; and see in any event next note.
[1] Adler suggests that this glossing phrase, for which there is no exact parallel, comes from a scholion on Gregory of Nazianzus.
[2] Likewise in the Ambrosian Lexicon, according to Adler; see also Etymologicum Magnum 522.26.
[3] Dative plural of the neuter noun kni=sos, with same glossing in other lexica (see the references at Photius kappa829 Theodoridis); evidently quoted from somewhere.