impĕtus (inp-), ūs (dat. impetu, Planc. ap. Cic. Fam. 10, 24, 3; no gen. plur.; abl. impetibus, Lucr. 1, 293; v. also impes), m. [impeto], an attack, assault, onset (freq. and class.; in sing. and plur. equally common).
I Lit.
A In gen.: incursio atque impetus armatorum, Cic. Caecin. 15, 44: gladiis destrictis in eos impetum fecerunt, Caes. B. G. 1, 25, 2: impetum facere in aliquem, id. ib. 1, 46 fin. ; Hirt. B. G. 8, 18, 4: in agros, Liv. 1, 5, 4: ad regem, id. 1, 5, 7; cf.: in hostes, Caes. B. G. 1, 22, 3: dare impetum in aliquem, Liv. 4, 28, 1; 2, 19, 7: capere impetum in aliquem, Plin. 9, 30, 48, § 91: hostes impetu facto celeriter nostros perturbaverunt, Caes. B. G. 4, 12, 1: oppidum magno impetu oppugnare, id. ib. 2, 6: primo hostium impetu pulsi, id. ib. 2, 24, 1: impetus gladiorum excipere, id. ib. 1, 52, 4: impetum sustinere, id. ib. 3, 2, 4: ferre impetum, id. ib. 3, 19, 3: fracto impetu levissimi hominis, Cic. Fam. 1, 5, b, 2: impetum propulsare, id. Mur. 1, 2: nec primum quidem impetum, nec secundum, nec tertium, sustinere potuerunt, Flor. 3, 3, 4; Liv. 33, 36, 11: uno impetu, Curt. 8, 14, 18; Lact. 3, 26, 10; 5, 4, 1: coërcere, Plin. 17, 22, 35, § 180: aquarum domare, id. 31, 6, 31, § 58: nec tantum (cupiditates) in alios caeco impetu incurrunt, etc., Cic. Fin. 1, 13, 44.— Poet.: biformato impetu Centaurus, with double - shaped attack , Cic. poët. Tusc. 2, 8 fin. ; v. biformatus.—
B In partic.
1 In medic. lang., an attack of a disease, a fit , paroxysm : febris, Cels. 2, 15: pituitae, Plin. 28, 12, 50, § 183: coeliacorum, id. 20, 14, 53, § 148: oculorum, i. e. inflammation , id. 20, 3, 8, § 16: thymum e vino tumores et impetus tollit, id. 21, 21, 89, § 157; so absol. , id. 22, 25, 58, § 122. —
2 In mechanics, the pressure of a load, Vitr. 6, 3.—
II Transf., in gen. (without reference to an object), violent impulse , violent or rapid motion , impetus , impetuosity , violence , fury , vehemence , vigor , force.
A Physical: labitur uncta carina, volat super impetus undas, Enn. ap. Macr. S. 6, 1 (Ann. v. 379 Vahl.): in magno impetu maris atque aperto, Caes. B. G. 3, 8, 1: Hebri, Phaedr. 3, prol. 59: impetus caeli, i. e. rapid motion , Cic. N. D. 2, 38, 97; Lucr. 5, 200. — Hence also poet.: quieti corpus nocturno impetu Dedi, in the nocturnal revolution , i. e. in the night , Att. ap. Cic. Div. 1, 22, 44: impetus ipse animaï Et fera vis venti, Lucr. 6, 591; cf.: tantos impetus ventorum sustinere, Caes. B. G. 3, 13, 6.—
B Mental, impulse , vehemence , ardor , passion , etc.
α Sing. : repentino quodam impetu animi incitatus, internal pressure , impulse , Cic. Off. 1, 15, 49; cf.: ut tota mente omnique animi impetu in rem publicam incumbas, id. Fam. 10, 5, 2; id. Att. 11, 5, 1: impetu magis quam consilio, Liv. 42, 29, 11: aliter in oratione nec impetus ullus nec vis esse potest, Cic. Or. 68, 229; cf.: ad omnem impetum dicendi, id. Deiot. 2, 5: actiones quae recitantur impetum omnem caloremque perdunt, Plin. Ep. 2, 19, 2: resumere impetum fractum omissumque, id. ib. 7, 9, 6: adulescens impetus ad bella maximi, Vell. 2, 55, 2: est prudentis, sustinere ut currum sic impetum benevolentiae, Cic. Lael. 17, 63: divinus impetus, id. Div. 1, 49, 111: si ex hoc impetu rerum nihil prolatando remittitur, Liv. 37, 19, 5: donec impetus famae et favor exercitus languesceret, Tac. Agr. 39 fin. : est mihi per saevas impetus ire feras, I feel an impulse , Ov. H. 4, 38: Bessus occidendi protinus regis impetum ceperat, had formed a sudden purpose , Curt. 5, 12, 1: statim moriendi impetum cepit, Suet. Oth. 9.— Prov.: Da spatium tenuemque moram, male cuncta ministrat impetus, haste makes waste , Stat. Th. 10, 704 sq.—
β Plur. : animalia, quae habent suos impetus et rerum appetitus, impulses , instincts , Cic. Off. 2, 3, 11: an fortitudo, nisi insanire coeperit, impetus suos non habebit? id. Tusc. 4, 22, 50: temperantia est rationis in libidinem atque in alios non rectos impetus animi firma et moderata dominatio, id. Inv. 2, 54, 164: insanos atque indomitos impetus vulgi cohibere, id. Rep. 1, 5.