The only other attestation of this (unglossed) headword ku/neiron is the one noted by Adler: Theognostus, Canones 121 (= Anecdota Oxoniensia [ed. Cramer] 2.21.23), where it seems to be an adjective -- in either the masculine accusative singular or the neuter nominative/accusative singular -- glossed as a(palo/n ('soft', in a bad way).
It is unclear whether there is a connection with the feminine noun ku/neira 'dog-leash', attested in Attic Comedy (Adespota fr. 1056 Kock, now 217 K.-A.) as a punning reference to the cunt; J. Henderson, The Maculate Muse (New Haven 1971) 133 #119.