A.on the ground, on the ground-floor, στοαὶ ἐ., opp. ὑπερῷοι, D.H.3.68, cf. PFlor.376.7 (iii A.D.); “σηκός” Aret.CA2.2.
II.. level, flat, Pl.Criti.112a; “χωρίον” X.HG7.1.29, etc.; οὐκ ἐν ἐπιπέδῳ, ἀλλὰ πρὸς ὀρθίῳ not on a level, but . . , ib.6.4.14; “ἐξ ἐπιπέδου” PThead.20i3 (iv A.D.); = Lat. de plano, J.AJ19.5.3: irreg. Comp. “-πεδέστερος” X.HG7.4.13.
III.. in Geom., plane, superficial, opp. στερεός (solid), Pl.Phlb.51c, Ti.32a; ἐ. γωνία a plane angle, ib.54e; ἡ τοῦ ἐ. πραγματεία plane geometry, Id.R.528d; μήκους καὶ ἐ. καὶ βάθους one-, two-, and three-dimensional magnitude, Id.Lg.817e; “εἰ κῶνος τέμνοιτο ἐπιπέδῳ” Democr.155.
2.. of numbers, representing a surface, Plu.2.367f, Nicom.Ar.2.7; ὁ ἰσόπλευρος καὶ ἐ. ἀριθμός a square number, Pl.Tht.148a. Adv. -δως Nicom.l.c.