A.striking or dashing together, πέτραι Συμπληγάδες the clashing rocks, i.e. the Κυάνεαι νῆσοι, which were supposed to close in on all who sailed between them (also called συνδρομάδες), E.IT355, cf. Str.1.2.10, 3.2.12; Κυάνεαι ς. π. E.Med.1263 (lyr.); Συμπληγάδες (sc. πέτραι) ib.2, IT260,1389: sg., κυανέαν Συμπληγάδα ib.241; Ἄξενον . . ἐκπερᾶσαι ποντίαν Ξυμπληγάδα, of the passage out of the Euxine (“ποντιᾶν Ξυμπληγάδων” Herm.), Id.Andr.794 (lyr.).
II. as Subst., collision, conflict, Arist.Mu.392b13, Him.Or. 19 tit.