Lewis & Short

prō-lābor, lapsus, 3, v. n., to glide forward, to slide or slip along, to fall down (class.; in Cic. most freq. in a trop. sense).

  1. I. Lit.: at Canis ad caudam serpens prolabitur Argo, Cic. poët. N. D. 2, 44, 114; Prop. 1, 20, 47: ruit prolapsa moles, of the sea, Att. ap. Cic. N. D. 2, 35, 89: collapsus pons, usque alterius initium pontis prolabi eum leniter cogebat: alii elephanti pedibus insistentes, alii clunibus subsidentes prolabebantur, to slide along … slide forward, Liv. 44, 5 sqq.: velut si prolapsus cecidisset, terram osculo contigit. id. 1, 56: equus prolapsum per caput regem effudit, falling down, id. 27, 32: ex equo, id. 27, 27: ex arbore altā prolapsus, Plin. 27, 8, 45, § 69; Ov. Ib. 223; cf.: prolapsus in cloacae foramen, Suet. Gram. 2: prolapsa Pergama, fallen down, fallen to ruin, Verg. A. 2, 555: Laodicea tremore terrae prolapsa, Tac. A. 14, 27.
  2. II. Trop.
    1. A. To go forward, go on, to proceed or come to, fall into any thing: me longius prolapsum esse, quam ratio vestri judicii postularit, have gone farther, i. e. have said more, Cic. Caecin. 35, 101: libenter ad istam orationem tecum prolaberer, would go on, be led on, id. Leg. 1, 20, 52: in misericordiam prolapsus est animus, Liv. 30, 12: in rabiem, Tac. A. 1, 31: ad seditiones, id. ib. 4, 18: ad jurgia, id. ib. 2, 10: ad superbiam, id. ib. 11, 17 fin.; Amm. 23, 6, 1.
    2. B. To slip out, escape: ne quod ab aliquā cupiditate prolapsum verbum videatur, Cic. Font. 13, 28 (9, 18).
    3. C. To fall, fail, err: timore, Cic. Quint. 24, 77: cupiditate, id. Att. 1, 17, 19: cupiditate regni, Liv. 40, 23: nimio juvandi mortales studio, Plin. 28, 8, 29, § 118.
    4. D. To fall to decay, to sink, decline, go to ruin: huc unius mulieris libido est prolapsa, ut, etc., Cic. Cael. 20, 47; cf.: eo prolapsi sunt mores, ut, etc., Sen. Contr. 15: ita prolapsa est (juventus), ut coërcenda sit, Cic. Div. 2, 2, 4: ad id prolapsae, Tac. A. 12, 53: in aliquod dedecus, Val. Max. 2, 1, 5: prolapsum clade Romanum imperium, Liv. 23, 5, 14: rem temeritate ejus prolapsam restituit, id. 6, 22; 45, 19: studio magnificentiae, Tac. A. 3, 55.
    5. E. To fall away from grace (eccl. Lat.), Vulg. Heb. 6, 6.