A.separating circle (cf. “ὁρίζω” 1.1b), horizon, Autol.Sph.5, Ti.Locr.97a ; “ὁτοῦ ὁρίζοντος κύκλος” Arist.Mete. 363a27 ; “ὁ ὁ. κύκλος” Id.Cael.297b34, al. ; ὁ αἰσθητὸς ὁ., opp. ὁ λόγῳ θεωρητός, Gem.5.56,57 ; “οἱ ὁρίζοντες” Ti.Locr.97d.
2. Pythag. name for 9, because it limits, i.e. finishes, the series of units, Theol.Ar.57.