Lewis & Short

rĕor, rătus, 2 (2 pers. pres. rere, Plaut. As. 3, 1, 22; id. Ep. 3, 4, 45; id. Trin. 2, 4, 13; Verg. A. 3, 381; 7, 437; Hor. S. 1, 9, 49: reris, Plaut. Bacch. 5, 2, 9; Verg. A. 6, 97; Hor. S. 2, 3, 134), v. dep. a. [etym. dub.; cf. Sanscr. rta, correct; Zend, areta, complete; Gr. ἀρετή, valor].

  1. I. To reckon, calculate; v. infra, P. a.
    Hence, by a usual transfer (like censere, putare, existimare, etc.),
  2. II. To believe, think, suppose, imagine, judge, deem (class.; esp. freq. in the poets; cf. Cic. de Or. 3, 38, 153; not in Cæs.: horridum reor, Quint. 8, 3, 26; cf.: opinor, arbitror, credo, censeo).
          1. (α) With obj.-clause: hoc servi esse officium reor, Plaut. Aul. 4, 1, 7; so, reor, id. Ep. 3, 4, 49; id. Pers. 2, 1, 2; id. Rud. 4, 2, 21; id. Truc. 2, 7, 16; Lucr. 5, 1419; Verg. A. 4, 45; 5, 24; 7, 273; 370; Hor. Ep. 2, 1, 70; Ov. M. 1, 394; 11, 438; 12, 505; Quint. 2, 16, 9 al.: reris and rere, v. supra: retur, Plaut. Am. 1, 1, 17; id. Ep. 3, 2, 32; id. Mil. 3, 1, 119; id. Truc. 1, 1, 72; Stat. Th. 11, 59: remur, Plaut. As. Grex. 6; Cic. Off. 2, 9, 32: remini, Arn. 4, 146: rentur, Plaut. Am. 3, 3, 20; id. Mil. 2, 6, 7; Lucr. 1, 155; 6, 91; Cic. Top. 20, 78; Liv. 1, 59; 5, 3; 24, 37; 40, 5 fin. Drak.: rebar, Ter. Hec. 4, 2, 5; Cic. de Or. 3, 22, 82; Verg. A. 6, 690; Ov. M. 13, 497; 14, 203: rebare, Cic. Att. 14, 8, 1: rebatur, id. Ac. 1, 7, 26; id. Att. 7, 3, 10; Liv. 9, 3; 27, 25; 30, 9 al.: rebamur, Plaut. Am. 5, 1, 43: rebantur, Cic. N. D. 3, 6, 15; Liv. 1, 26; 3, 41; 4, 1 et saep.: rebor, Sen. Herc. Fur. 303: rebitur, Plaut. Aul. 2, 2, 28: rear, id. Most. 1, 3, 2; Cat. 63, 55; Verg. A. 9, 253: rearis, Lucr. 1, 80; 2, 731; 5, 114; 247; 6, 536 al.: reare, Caecil. ap. Gell. 617, 13: reamur, Lucr. 2, 952; 4, 37; 5, 78; 6, 764: reantur, Plaut. Ps. 1, 2, 34: ratus sum, etc., sim, etc., id. As. 5, 2, 11; id. Capt. 2, 2, 6; id. Ep. 4, 2, 26 al.; Ter. Hec. 5, 3, 21; Verg. A. 2, 25; Ov. M. 4, 674; 5, 203; 7, 841 al.; Sall. C. 48, 5; 55, 1; Liv. 2, 27; 3, 2; Quint. 11, 3, 31; 12, 10, 5 et saep. al.
          2. (β) Absol., Plaut. Cas. 2, 6, 4: quos quidem plures, quam rebar, esse cognovi, Cic. Div. 2, 2, 5: jam illud mali plus nobis vivit quam ratae (sc. sumus), Plaut. Rud. 2, 4, 32: ut reor a facie, Calliopea fuit, Prop. 3, 3 (4, 2), 38: ut rebare, Venus (nec te sententia fallit) Trojanas sustentat opes, Verg. A. 10, 608: ut potius reor, id. ib. 12, 188: atque, ut ipse rebatur viam suāpte naturā difficilem inexpugnabilem fecit, Liv. 31, 39, 9: nam, reor, non ullis, si vita longior daretur, posset esse jucundior, Cic. Tusc. 1, 39, 94.
            Hence, ră-tus, a, um, P. a., pass., reckoned, calculated, fixed by calculation; hence, fixed, settled, established, firm, unalterable, sure, certain, valid, etc. (class.): quod modo erat ratum inritumst, Ter. Phorm. 5, 8 (7), 58: neu quod egissem esset ratum, id. Hec. 4, 1, 30: rata et certa spatia definire, Cic. Tusc. 5, 24, 69: motus (stellarum) constantes et rati, id. N. D. 2, 20, 51: astrorum rati immutabilesque cursus, id. ib. 2, 37, 95; 2, 38, 97: si nihil fieri potest, nisi quod ab omni aeternitate certum fuerit esse futurum rato tempore, id. Div. 2, 7, 19; 2, 30, 63: jussum ratum atque firmum, id. Caecin. 33, 96: decretum stabile, fixum, ratum esse debeat, id. Ac. 2, 9, 27: illud certum, ratum, firmum, fixum vis, id. ib. 2, 46, 141: censorias subscriptiones omnes fixas et in perpetuum ratas putet esse, id. Clu. 47, 132; cf.: ut amicitia societasque nostra in aeternum rata sit, Tac. H. 4, 64: cujus tribunatus si ratus est, nihil est, quod irritum possit esse, Cic. Prov. Cons. 19, 45; cf. so, opp. irritus, id. Phil. 5, 7, 21; cf. ratosne habeant an vanos pectoris orsus, id. poët. Div. 2, 30, 63: testamenta (opp. rupta), id. de Or. 1, 38, 173: populi comitia ne essent rata, nisi, etc., id. Rep. 2, 32, 56: ut Faustae, cui cautum ille voluisset, ratum esset, id. Att. 5, 8, 2: neque ratum est quod dicas, Att. ap. Fest. p. 228; Nep. Att. 10, 1: dixerat idque ratum Stygii per flumina Annuit, Verg. A, 9, 104: si haec Turno rata vita maneret, id. ib. 10, 629: rata sint sua visa precatur, may be fulfilled, accomplished, Ov. M. 9, 702; 9, 474; 14, 815; 3, 341; id. H. 15 (16), 15; id. F. 1, 696; 3, 77; id. P. 2, 5, 3; cf.: (ebrietas) spes jubet esse ratas, Hor. Ep. 1, 5, 17: pax, Sall. J. 112, 3: fides et vox, Ov. M. 3, 341; id. Tr. 3, 10, 36: dicta, id. F. 2, 488.
            Sup.: beneficia ratissima atque gratissima, Cato ap. Fest. pp. 286 and 287 Müll.
            Poet., transf., of a person: occiduntur: ubi potitur ratu’ Romulu’ praedam, the resolved, determined (syn. certus), Enn. ap. Fest. p. 274 Müll. (Ann. v. 78 Vahl.).
            Hence,
    1. B. In particular connections.
      1. 1. Pro ratā parte (portione), secundum ratam partem, and absol., pro ratā, according to a certain part, i. e. in proportion, proportionally: militibus agros ex suis possessionibus pollicetur, quaterna in singulos jugera, et pro ratā parte centurionibus evocatisque, Caes. B. C. 1, 17 fin.; cf.: pro ratā parte, Cic. Rep. 6, 18, 18 Mos. N. cr.: perinde ut cuique data sunt pro ratā parte, id. Tusc. 1, 39, 94: utinam ex omni senatu pro rata parte esset! id. Rep. 2, 40, 67: decumam partem relinqui placet, si plenae fuerint alvi, si minus, pro ratā portione, Plin. 11, 15, 15, § 40: item secundum ratam partem ex altitudine columnarum expediendae sunt altitudines epistyliorum, Vitr. 3, 3 med.: tantum pediti daturum fuisse credunt, et pro ratā aliis, si, etc., Liv. 45, 40; so Capitol. M. Aur. 7, and often in the Digests.
      2. 2. Ratum aliquid facere (efficere) habere, ducere, also ratum alicui esse, to make or account any thing fixed or valid; to confirm, ratify, approve: quid augur (habet), cur a dextrā corvus a sinistrā cornix faciat ratum? make a confirmatory, i. e. a favorable augury, Cic. Div. 1, 39, 85: parens nati rata verba Fecit, i. e. fulfilled, Ov. M. 4, 387: juvenes cum avum regem salutassent, secuta ex omni multitudine consentiens vox ratum nomen imperiumque regi effecit, Liv. 1, 6: efficiant ratas, utraque diva preces, Ov. F. 1, 696: quae nobis imperatores commoda tribuerunt, ea rata atque perpetua auctoritate vestrā faciatis, Liv. 28, 39, 16: eos ratum habere judicium, si totum corruptum sit; si unus accusator corruptus sit, rescindere, Cic. Part. Or. 36, 125; so, ratum habere, id. Rosc. Com. 1, 3; id. Att. 14, 21, 2; id. N. D. 1, 5, 10: Atteius Capito ap. Gell. 13, 12, 2; cf.: (fata) ratosne habeant an vanos pectoris orsus, Cic. poët. Div. 2, 30, 63: cavere de rato, Dig. 3, 4, 6, § 3: qui non duxerint societatem ratam, ubi nec divini quicquam nec humani sanctum esset, Liv. 27, 17 fin.: ista ipsa, quae te emisse scribis, non solum rata mihi erunt, sed etiam grata, Cic. Fam. 7, 23, 1.
        Rarely, ratum servare: quaeris an quod gessit ratum servum. Ego vero servo, Plin. Ep. 7, 11, 1.
        Note: In Liv. 25, 12, for the corrupted curata auctoritas eventu of the MS., read cum rato auctoritas eventu; v. Weissenb. ad h. l.