Lewis & Short

lăbo, āvi, ātum, 1, v. n. [from the same root as 1. labor], to totter, be ready to fall, begin to sink, to give way, be loosened (syn.: vacillo, titubo, nato).

  1. I. Lit.: labat, labuntur saxa, caementae cadunt, Enn. ap. Non. 196, 3 (Trag. v. 142 Vahl.): signum labat, Cic. Verr. 2, 4, 43, 95: si ex ictu … labant dentes, Cels. 7, 12, 1: labat ariete crebro Janua, Verg. A. 2, 492: labant curvae naves, roll, Ov. M. 2, 163: pressaeque labant sub gurgite turres, id. ib. 1, 290: (turris) qua summa labantis Juncturas tabulata dabant, Verg. A. 2, 463: littera labat, written with a trembling hand, Ov. H. 10, 140: labare sermone, to stutter, speak indistinctly, Plin. 14, 22, 28, § 146: si labat oculus et hac atque illac movetur, is unsteady, Cels. 7, 7, 14: tarda trementi genua labant, sink, Verg. A. 5, 432; so, pedes, Ov. F. 6, 676: vincla labant, are loosed, id. A. A. 2, 85.
    Poet., of dying persons: inde labant populi, fall, sink, Luc. 6, 93; cf.: omnia tum vero vitaï claustra lababant, Lucr. 6, 1153.
    With Gr. acc.: egressi labant vestigia prima, Verg. A. 10, 283 Forbig. (Rib. egressisque).
  2. II. Trop.
    1. A. To waver, to be unstable, undecided, to hesitate (in opinion, resolution, etc.): si res labat, Itidem amici collabascunt, Plaut. Stich. 4, 1, 16; cf.: scito, labare meum consilium illud, quod satis jam fixum videbatur, Cic. Att. 8, 14, 2: labamus mutamusque sententiam, id. Tusc. 1, 32, 78: cum ei labare M. Antonius videretur, id. Phil. 6, 4, 10: animumque labantem inpulit, Verg. A. 4, 22: labantia corda, id. ib. 12, 223: socii labant, waver in fidelity, Liv. 22, 61; cf.: fides sociorum, id. 32, 30, 9: animus regis, id. 40, 54; 2, 39: quīs lababat fides, whose fidelity was wavering, Sil. 2, 392: mens, Ov. M. 6, 629: tu mente labantem dirige me, Luc. 2, 244: ex nimia matrem pietate labare sensit, Ov. M. 6, 629: memoria labat, becomes weak, Liv. 5, 18; cf.: mens in illis (phreneticis) labat, in hoc (cordiaco) constat, Cels. 3, 19: nec dubium habebatur labare hostes, Tac. A. 2, 26: labante jam Agrippina, id. H. 14, 22: labantem ordinem contirmare, Suet. Caes. 14: acies labantes restituere, Tac. G. 8 init.: sustinere labantem aciem, id. H. 3, 23; 5, 18.
    2. B. To sink, fall to pieces, go to ruin: quid non sic aliud ex alio nectitur, ut non, si unam litteram moveris, labent omnia? Cic. Fin. 3, 22, 74: omnes rei publicae partes aegras et labantes sanare et confirmare, id. Mil. 25, 68; cf.: sustinuisse labantem fortunam populi Romani, Liv. 26, 41: sicuti populo Romano sua fortuna labet, id. 42, 50: labante egregia quondam disciplina, id. 36, 6: cum res Trojana labaret, Ov. M. 15, 437: labantibus Vitellii rebus, Tac. H. 2, 86: si quid in moribus labaret, id. A. 2, 33.