I.that does not stand fast, unsteady, unstable, tottering, not firm (mostly poet.; syn. varius, mutabilis, vagus; not in Cic.).
I. Lit.: “sic erat instabilis tellus,” Ov. M. 1, 16: “locus ad gradum instabilis,” Tac. A. 1, 64: “(with lubricus) gradus,” Curt. 8, 11, 13: “ingressus,” Liv. 24, 34, 15: “vestigium,” Plin. Pan. 22, 4: “volutatio,” Plin. 31, 6, 33, § 63: “cymbae,” Verg. G. 4, 195: “naves,” Curt. 4, 2, 9.—Transf., unsteady, i. e. that does not keep its ground: “(with fluctuans) acies,” Liv. 9, 35, 6: “hostis,” id. 27, 18, 14.—
II. Trop., unstable, inconstant, changeable, fickle: insanam aiunt (Fortunam), quia atrox, incerta instabilisque sit, Pac. ap. Auct. Her. 2, 23, 36: res maritimae celerem atque instabilem mo tum habent, Caes. B. G. 4, 23: “nihil tam instabile ac fluxum est, quam fama,” Tac. A. 13, 19: “fortuna,” id. H. 4, 47: “conjugium,” Juv. 9, 79: “animus,” Verg. G. 4, 105 (but read insatiabiles, Curt. 7, 8, 19). — Adv.: instă-bĭlĭter , unsteadily, Aug. Conf. 13, 20.