Lewis & Short

2. certo, āvi, ātum, 1, v. freq. a. [cerno], to decide something by a contest (cf. cerno, II. C. b.); hence, to fight, struggle, contend, combat, implying great exertion, and usually a measuring of strength (class. in prose and poetry; most freq. in a trop. signif.; syn.: decerto, contendo).

  1. I. Of a physical contest of strength; mostly of battle: utrum igitur utilius Fabricio … armis cum hoste certare, an venenis? Cic. Off. 3, 22, 87: adulescentium greges Lacedaemone videmus ipsi incredibili contentione certantis pugnis, calcibus, unguibus, morsu denique, id. Tusc. 5, 27, 77: manu, Sall. H. 2, 41, 6 Dietsch: proelio, id. J. 81, 3: cum Gallis pro salute, id. ib. 114, 2; cf. Tac. Agr. 5: de ambiguo agro bello, Liv. 3, 71, 2: de imperio cum populo Romano, Cic. de Or. 2, 18, 76: de principatu armis, Tac. H. 2, 47; cf. Suet. Vesp. 5: odiis etiam prope majoribus certarunt quam viribus, Liv. 21, 1, 3: acie, Verg. A. 2, 30 et saep.
    Impers.: dignus quicum certetur, Pac. ap. Non. p. 473, 16: certatur limine in ipso Ausoniae, Verg. A. 10, 355; 11, 313: die quo Bedriaci certabatur, Tac. H. 2, 50: quā in parte rex pugnae affuit, ibi aliquamdiu certatum, Sall. J. 74, 3: in cujus (amnis) transgressu multum certato pervicit Vardanes, Tac. A. 11, 10; id. H. 4, 61.
    Mostly poet. in pass.: certata lite deorum Ambracia (for the possession of which Apollo. Diana, and Hercules contended), Ov. M. 13, 713: certatus nobis orbis (i. e. de quo certavimus), Sil. 17, 342; cf. II. infra.
  2. II. Out of the sphere of milit. operations, to contend, struggle, strive, emulate, vie with: certabant urbem Romam Remoramne vocarent, Enn. ap. Cic. Div. 1, 48, 107 (Ann. v. 85 Vahl.): haut doctis dictis certantes sed maledictis, Enn. ap. Gell. 20, 10, 4 (Ann. v. 274 ib.): minis mecum, minaciis, Plaut. Truc. 5, 56: malitiā tecum, id. Pers. 2, 2, 56: benedictis, Ter. Phorm. prol. 20: certare ingenio, contendere nobilitate, Lucr. 2, 11: cum aliquo dicacitate, Cic. Brut. 46, 172: officiis inter se, id. Fam. 7, 31, 1; cf.: certatum inter collegas maledictis, Liv. 5, 8, 13; and: eo modo inter se duo imperatores certabant, Sall. J. 52, 1: cum civibus de virtute, id. C. 9, 2: pro sua quisque potentia, id. ib. 38, 3: contumaciā adversus contemnentes humilitatem suam nobiles certavit (Licinius), Liv. 9, 46, 4: cum usuris fructibus praediorum, to contend against interest (to strive to pay interest) with the produce of estates, Cic. Cat. 2, 8, 18: cum a Cheruscis Longobardisque pro antiquo decore aut recenti libertate; et contra, augendae dominationi certaretur, Tac. A. 2, 46: ob hircum, Hor. A. P. 220: joco, id. C. 2, 12, 18: mero, id. ib. 4, 1, 31: animis iniquis, Verg. A. 10, 7: parsimoniā et vigiliis et labore cum ultimis militum, Liv. 34, 18, 5: sententiis, Tac. A. 1, 29 al.: ut si nautae certarent, quis eorum potissimum gubernaret, Cic. Off. 1, 25, 87: mos gentis est, equitare jaculari cursu cum aequalibus certare, Sall. J. 6, 1: dic mecum quo pignore certes, Verg. E. 3, 31: celeri sagittā, id. A. 5, 485: certemus, spinas animone ego fortius an tu Evellas agro, Hor. Ep. 1, 14, 4.
    Poet., with acc.: hanc rem ( = de hac re), Sedigit. ap. Gell. 15, 24; cf. in pass.: cui (multae) certandae cum dies advenisset, Liv. 25, 3, 14.
    With dat. instead of cum: solus tibi certat Amyntas, Verg. E. 5, 8; Hor. S. 2, 5, 19; id. Epod. 11, 18; 2, 20; id. C. 2, 6, 15; Verg. E. 8, 55; id. G. 2, 138; Ov. M. 14, 794.
      1. 2. Particularly of judicial disputations, to contend at law: inter se, Cic. Verr. 2, 2, 16, § 39; cf. id. ib. 2, 2, 13, § 32: in centumvirali judicio, id. de Or. 1, 39, 177: si a duumviris provocarit, provocatione certato, Liv. 1, 26, 6: si quid se judice certes, Hor. S. 2, 1, 49: foro si res certabitur olim, id. ib. 2, 5, 27.
      2. 3. With inf. (mostly poet.), to strive to do something, to labor, endeavor, struggle earnestly, to exert one’s self: certantes ad summum succedere honorem, Lucr. 5, 1123; so, inter se cernere, id. 5, 394: dimittere se (nubes), id. 6, 509: populum alium suorum sepelire, id. 6, 1247: Phoebum superare canendo, Verg. E. 5, 9: superare, Ov. M. 5, 394: vincere, Verg. A. 5, 194: tollere (hunc) tergeminis honoribus, Hor. C. 1, 1, 8: inter se eruere quercum, Verg. A. 4, 443: certat quisque evadere, Curt. 9, 4, 33: frangere fluctus, Plin. Pan. 81 fin.; Sil. 13, 222; Stat. S. 5, 3, 191.