ῥόμβος or ῥύμβος, ὁ, (ῥέμβω) bull-roarer, instrument whirled round on the end of a string, used in the mysteries, ῥόμβου θ᾽ εἱλισσομένα κύκλιος ἔνοσις αἰθερία E.1362, cf. Archyt.1, Theoc.2.30; as a boy's toy, 6.309 (Leon.), Orph.31.29, 34, M.Ant.5.36; defined as ξυλήφιον, οὗ ἐξῆπται τὸ σπαρτίον, καὶ ἐν ταῖς τελεταῖς ἐδονεῖτο, ἵνα ῥοιζῇ, Sch.Clem.Al.2.17.2, cf. Hsch. magic wheel, spun alternately in each direction by the torsion of two cords passed through two holes in it, used as a love-charm, Luc. 4.5; called ἴυγξ in Theoc.2.17, 5.204; Lat. rhombus, Prop.2.28.35, Ov.1.8.7. τροχίσκος ὃν στρέφουσιν ἱμᾶσι τύπτοντες, καὶ οὕτως κτύπον ἀποτελοῦσι Sch. A.R. 1.1134; ὦ ῥύμβε μαστίξας ἐμέ (dub. sens.) Eup.72. tambourine or kettle-drum, used in the worship of Rhea and of Dionysus, Ar.303, Diog.Ath.1.3, A.R. 1.1139, 6.165 (Phal.); ῥύμβος ξύλινος ἐπίχρυσος 22.1456.49, cf. 1517.207. membrum virile, PLond.1821.164. whirling motion, as of a bull-roarer, ἀκόντων ἱέντα ῥόμβον shooting forth whirling darts, Pi.13.94; αἰετοῦ ῥ. the eagle's swoop, Id.4(3).47(65); ῥ. τυπάνων Id.1604 1 ii 9; ἐν αἰθερίῳ ῥύμβῳ Critias 19.2D.; ῥόμβου ἀπειρεσίου δινεύμασιν οἶμον ἐλαύνων, of the Sun, Orph. 8.7: metaph., Νέμεσις καὶ ῥ. ἀλάστωρ 14.1389ii34 (perh. an Adj., = ῥεμβός).—The Gramm. hold ῥύμβος to be Att., ῥόμβος Hellenic, Sch.Theoc.2.30, Ath.7.330b. rhombus, lozenge, i.e. a four-sided figure with all the sides, but only the opposite angles, equal, Arist.854b16, Euc.1 22. ῥ. στερεός, a figure composed of two cones on opposite sides of the same base, Archim.1.26, al. a species of fish, of which turbot and brill are varieties, so called from its rhomblike shape, Nausicr.2.13; Ῥωμαῖοι καλοῦσι τὴν ψῆτταν ῥ. Ath.7.330b, cf. ψῆττα. surgical bandage, so called from its shape, Hp. 7, Heliod. ap. Orib.48.20.14. pattern of the same shape, in weaving cloth, Democr.Eph.1; διαπλοκὴ ῥόμβων Aristeas 74.