ingrŭo, ŭi, 3, v. n. [in-ruo, with an epenth. g from gruo, kindr. with κρούω], to rush or break into, to fall violently upon, assail, attack (syn. incumbo; differing from immineo and impendo, in that it denotes the actual doing of that which they merely threaten; not in Cic. or Caes.).
I Lit.: hostes crebri cadunt; nostri contra ingruunt, Plaut. Am. 1, 1, 81: ingruit Aeneas Italis, Verg. A. 12, 628; cf.: ingruere hostes, id. ib. 11, 899: simul ingruunt saxa jaciunt, Tac. A. 1, 27: ingruentes accusatores, id. ib. 6, 38: ingruente in Italiam Hannibale, id. H. 3, 34.—
II Transf., of things: ferreus ingruit imber, Verg. A. 12, 284: umbra vitibus, id. G. 2, 410: nox, Tac. A. 4, 50: tela, id. ib. 1, 65: ingruere morbi in remiges coeperunt, Liv. 37, 23, 2: si bellum ingrueret, Verg. A. 8, 535; Tac. A. 1, 48: si nullus ingruat metus, Plin. 9, 30, 50, § 95: si quid subitum ingruat, Tac. A. 4, 2: damnatio, id. ib. 4, 35.