A.pin or pivot on which a body or machine turns, “καθάπερ ἐπὶ κνώδακος τῆς τοῦ δευτέρου σπονδύλου ἀποφύσεως ἡ κεφαλὴ ἐπιστρέφεται” Gal.14.720, cf. 723; axis of a sphere, Orph.Fr.247.26: more freq. in pl., Hero Spir.1.43, S.E.M.10.93, Orib.49.22.21.
II. pl., sockets in which the axes of a drum turn, Ph.Bel.75.45.