κοίλωσις
From LSJ
χαῖρ', ὦ μέγ' ἀχρειόγελως ὅμιλε, ταῖς ἐπίβδαις, τῆς ἡμετέρας σοφίας κριτὴς ἄριστε πάντων → all hail, throng that laughs untimely on the day after the festival, best of all judges of our poetic skill
English (LSJ)
εως, ἡ,
A cavity, Hp.Carn.15, Sor.1.82; hollowing out, of flutes, Nicom.Harm.4,10 (pl., κοιλιώς- codd.).
German (Pape)
[Seite 1467] ἡ, richtigere Lesart für κοιλίωσις Nicom. Harm. p. 172.