A.with equal sides, “πλαίσιον” X.An.3.4.19, etc.: freq. in Geom., equilateral, “τρίγωνον” Pl.Ti.54a, 54e; ἐπίπεδον ib.55e; “τετράγωνον” Plb.6.31.10.
II. of numbers, square, opp. ἑτερομήκης, Pl.Tht.148a, Arist.APo.73a40. Adv. “-πλεύρως” Nicom.Ar.2.13.
III. Rhet., of periods, Hermog. Inv.4.3.