Evidently a proper name, but securely attested only here and, according to Adler, in the Ambrosian Lexicon. Possibly a feminine counterpart of *kerku/wn ~ *kerkuw/n (kappa 1412). Pape-Benseler record *kerkuoneu/s as an epithet of Apollo in inscriptions.
However, Aeschylus fr. 153 Mette indicates that the title of Aeschylus' satyr play Kerkyon was transmitted in at least one Byzantine lexicon [noted at Photius epsilon2240 Theodoridis, citing Hesychius epsilon6960] in the dative *kerkuo/nh| rather than the correct *kerkuo/ni; the incorrect form corresponds to the name in this entry. This gives a plausible origin for the entry.