Lewis & Short

aut, conj. [aut, Osc. auti, Umbr. ote, ute, may be a modification of autem, as at of et, the suffix -t being a relic of the demonstrative -tem, which appears in item, and is the same as -dem in quidem, and -dam in quondam, and of which the demonstrative adverbs, tam and tum, are absolute forms; the first part of these words may be compared with the Gr. αὖ (cf. αὖτε and αὐτάρ), and with the Sanscr. vā = or, with which again may be compared ve and vel; v. Corss. Ausspr. II. p. 595, and also pp. 130, 223, 411], or; and repeated: aut … aut, either … or; so in Sanscr. vā … vā.

  1. I. In gen. it puts in the place of a previous assertion another, objectively and absolutely antithetical to it, while vel indicates that the contrast rests upon subjective opinion or choice; i. e. aut is objective, vel subjective, or aut excludes one term, vel makes the two indifferent.
        1. a. Used singly, or: omnia bene sunt ei dicenda, qui hoc se posse profitetur aut eloquentiae nomen relinquendum est, Cic. de Or. 2, 2, 5: quibusnam manibus aut quibus viribus, Caes. B. G. 2, 30: Vinceris aut vincis, Prop. 2, 8, 10: cita mors venit aut victoria laeta, Hor. S. 1, 1, 8: ruminat herbas aut aliquam in magno sequitur grege, Verg. E. 6, 55 et persaep. (cf. on the contrary, Tac. G. 8: quae neque confirmare argumentis, neque refellere in animo est: ex ingenio suo quisque demat vel addat fidem).
        2. b. Repeated, aut … aut, either … or: Ubi enim potest illa aetas aut calescere vel apricatione melius vel igni, aut vicissim umbris aquisve refrigerari salubrius? Cic. Sen. 16, 57: Nam ejus per unam, ut audio, aut vivam aut moriar sententiam, Ter. Phorm. 3, 1, 19; id. Heaut. 3,1,11 sq.: aut, quicquid igitur eodem modo concluditur, probabitis, aut ars ista nulla est, Cic. Ac. 2, 30, 96: partem planitiae aut Jovis templum aut oppidum tenet, Liv. 44, 6, 15: terra in universum aut silvis horrida aut paludibus foeda, Tac. G. 5: hoc bellum quis umquam arbitraretur aut ab omnibus imperatoribus uno anno aut omnibus annis ab uno imperatore confici posse? Cic. Imp. Pomp. 11,31.
        3. c. More than twice repeated: aut equos Alere aut canes ad venandum, aut ad philosophos, Ter And. 1, 1, 29: Uxor, si cesses, aut te amare cogitat Aut tete amare aut potare atque animo obsequi, id. Ad. 1, 1, 7 sq.; so four times in Lucr. 4, 935 sq.; five times in Cic. Off. 1, 9, 28; id. N. D. 3, 12, 30; and Prop. 4, 21, 26 sqq.; and six times in Plin. 17, 10, 9, § 58.
        4. d. Sometimes double disjunctive phrases with aut … aut are placed together: Adsentior Crasso, ne aut de C. Laelii soceri mei aut de hujus generi aut arte aut gloriā detraham, Cic. de Or. 1, 9, 35: res ipsa et rei publicae tempus aut me ipsum, quod nolim, aut alium quempiam aut invitabit aut dehortabitur, id. Pis. 39, 94.
        5. e. Repeated after negatives: ne aut ille alserit Aut ceciderit atque aliquid praefregerit, Ter. Ad. 1, 1, 11: ne tanti facinoris immanitas aut exstitisse aut non vindicata esse videatur, Cic. Cat. 1, 6, 14; id. Sull. 43; id. Sest. 37; 39: neque enim sunt aut obscura aut non multa post commissa, id. Cat. 1, 6, 15; id. Off. 1, 20, 66; 1, 11, 36; 1, 20, 68; id. de Or. 2, 45, 189: nec milites ad scelus missos aut numero validos aut animo promptos, Tac. A. 14, 58; id. H. 1, 18; id. Or. 12: nec erit mirabilis illic Aut Stratocles aut cum molli Demetrius Haemo, Juv. 3, 98 sq.: neque aut quis esset ante detexit aut gubernatorem cedere adversae tempestati passus est, Suet. Caes. 58; id. Ner. 34: Nec aut Persae aut Macedones dubitavere, Curt. 4, 15, 28: Non sum aut tam inhumanus aut tam alienus a Sardis. Cic. Scaur. 39; id. Cat. 1, 13: Nihil est tam aut fragile aut flexibile quam etc., id. Mil. 36 al.
        6. f. In interrogations: quo modo aut geometres cernere ea potest, quae aut nulla sunt aut internosci a falsis non possunt aut is, qui fidibus utitur, explere numeros et conficere versus? Cic. Ac. 2, 7, 22; so id. de Or. 1, 9, 37; id. Rosc. Am. 40, 118; id. N. D. 1, 43, 121.
        7. g. In comparative clauses: talis autem simulatio vanitati est conjunctior quam aut liberalitati aut honestati, Cic. Off. 1, 15, 44.
  2. II. Esp.
    1. A. Placed singly, to connect to something more important that which is less so, or at least.
        1. a. Absol.: Incute vim ventis submersasque obrue puppes, Aut age diversos et dissice corpora ponto, Verg. A. 1, 69 sq. Rib. (furens Juno et irata, quod gravissimum credebat, optavit, deinde quod secundum intulit, Diom. p. 411 P.): quaero, num injuste aut improbe fecerit, or at least unfairly, Cic. Off. 3, 13, 54: a se postulari aut exspectari aliquid suspicantur, id. ib. 2, 20, 69: quā re vi aut clam agendum est, or at least by stealth, id. Att. 10, 12: profecto cuncti aut magna pars Siccensium fidem mutavissent, Sall. J. 56, 6: Audendum est aliquid universis aut omnia singulis patienda, Liv. 6, 18, 7: pars a centurionibus aut praetoriarum cohortium militibus caesi, Tac. A. 1, 30: potentiā suā numquam aut raro ad impotentiam usus, Vell. 2, 29.
        2. b. With certe, etc., v. infra, F. 2.
    2. B. To connect something which must take place, if that which is previously stated does not, or, otherwise, or else, in the contrary case, = alioqui: Redduc uxorem, aut quam obrem non opus sit cedo, Ter. Hec. 4, 4, 76: id (principium) nec nasci potest nec mori, aut concidat omne caelum etc., Cic. Tusc. 1, 23, 54 (Seyffert ad h. l., but preferring ut non; B. and K. and Kühner, vel): nunc manet insontem gravis exitus: aut ego veri Vana feror, Verg. A. 10, 630: effodiuntur bulbi ante ver: aut deteriores fiunt, Plin. 19, 5, 30, § 96: Mutatione recreabitur sicut in cibis … Aut dicant iste mihi, quae sit alia ratio discendi, Quint. 1, 12, 6; 2, 17, 9.
    3. C. To restrict or correct an expression which is too general or inaccurate, or, or rather, or more accurately.
        1. a. Absol.: de hominum genere, aut omnino de animalium loquor, Cic. Fin. 5, 11, 33; 5, 20, 57; id. Ac. 2, 8, 23: Aut scilicet tua libertas disserendi amissa est, aut tu is es, qui in disputando non tuum judicium sequare, id. Leg. 1, 13, 36: cenaene causā, aut tuae mercedis gratiā Nos nostras aedīs postulas comburere? or rather, etc., Plaut. Aul. 2, 6, 11.
          In this signification aut sometimes begins a new clause: Potestne igitur quisquam dicere, inter eum, qui doleat, et inter eum, qui in voluptate sit, nihil interesse? Aut, ita qui sentiet, non apertissime insaniat? or is not rather, etc., Cic. Ac. 2, 7, 20: Quid est enim temeritate turpius? Aut quid tam temerarium tamque indignum sapientis gravitate atque constantiā, quam, etc., id. N. D. 1, 1, 1; id. Fin. 4, 26, 72; Plin. Ep. 1, 10, 3.
        2. b. With potius (v. infra, F. 4.).
    4. D. Neque … aut sometimes, but chiefly in the poets, takes the place of neque … neque: Neque ego hanc abscondere furto Speravi, ne finge, fugam; nec conjugis umquam Praetendi taedas aut haec in foedera veni, Verg. A. 4, 339: Si neque avaritiam neque sordes aut mala lustra Obiciet vere quisquam mihi, Hor. S. 1, 6, 68 Bentl., but ac, K. and H.: Nunc neque te longi remeantem pompa triumphi Excipit aut sacras poscunt Capitolia lauros, Luc. 1, 287: Nam neque plebeiam aut dextro sine numine cretam Servo animam, Stat. S. 1, 4, 66: Neque enim Tyriis Cynosura carinis Certior aut Grais Helice servanda magistris, Val. Fl. 1, 17; so also Tacitus: nec litore tenus adcrescere aut resorberi, Agr. 10; G. 7 ter; H. 1, 32; so after non: Non eo dico, quo mihi veniat in dubium tua fides, aut quo etc., Cic. Quinct. 5: non jure aut legibus cognoscunt, Tac. Or. 19; id. Agr. 41; id. G. 24; after haud: Haud alias populus plus occultae vocis aut suspicacis silentii permisit, id. A. 3, 11; after nihil: nihil caedis aut praedae, id. A. 15, 6; 13, 4; id. H. 1, 30.
    5. E. The poets connect by aut … vel, vel … aut, instead of aut … aut, or vel … vel: Quotiens te votui Argu rippum Conpellare aut contrectare conloquive aut contui? Plaut. As. 3, 1, 19: aut appone dapes, Vare, vel aufer opes, Mart. 4, 78, 6 (this epigram is rejected by Schneid.): Non ars aut astus belli vel dextera deerat, Sil. 16, 32.
  3. F. In connection with other particles.
      1. 1. Aut etiam, to complete or strengthen an assertion, or also, or even: quid ergo aut hunc prohibet, aut etiam Xenocratem, etc., Cic. Tusc. 5, 18, 51: conjectura in multas aut diversas, aut etiam in contrarias partes, id. Div. 2, 26, 55; id. Off. 1, 9, 28: si aut ambigue aut inconstanter aut incredibiliter dicta sunt, aut etiam aliter ab alio dicta, id. Part. Or. 14, 51: etsi omnia aut scripta esse a tuis arbitror, aut etiam nuntiis ac rumore perlata, id. Att. 4, 1.
        So with one aut: quod de illo acceperant, aut etiam suspicabantur, Cic. Fam. 1, 19, 36; Cels. 4, 18: si modo sim (orator), aut etiam quicumque sim, Cic. Or. 3, 12; id. de Or. 1, 17, 76.
      2. 2. Aut certe, aut modo, aut quidem, or aut sane, to restrict a declaration, or at least (cf. II. A.).
        1. a. Aut certe: ac video hanc primam ingressionem meam aut reprehensionis aliquid, aut certe admirationis habituram, Cic. Or. 3, 11; id. Top. 17, 64: quo enim uno vincebamur a victā Graeciā, id aut ereptum illis est, aut certe nobis cum illis communicatum, id. Brut. 73, 254; so Dolabella ap. Cic. Fam. 9, 9, 1; Liv. 2, 1, 4; 40, 46, 2; Cels. 1, 2; 5, 26; Prop. 4, 21, 29.
        2. b. Aut modo: Si umquam posthac aut amasso Casinam, aut obcepso modo, Plaut. Cas. 5, 4, 22.
        3. c. Aut quidem: Proinde desinant quidam quaerere ultra aut opinari … aut quidem vetustissimā nave impositos jubebo avehi, Suet. Caes. 66.
        4. d. Aut sane: Afer aut Sardus sane, Cic. Scaur. 15.
      3. 3. Aut vero, to connect a more important thought, or indeed, or truly: Quem tibi aut hominem, aut vero deum, auxilio futurum putas? Cic. Verr. 2, 4, 78: Quis enim tibi hoc concesserit, aut initio genus hominum se oppidis moenibusque saepsisse? Aut vero etc., id. de Or. 1, 9, 36.
      4. 4. Aut potius, for correction or greater definiteness, or rather (cf. II. C.): Erravit, aut potius insanivit Apronius? Cic. Verr. 2, 3, 119: proditores aut potius apertos hostes, id. Sest. 35: nemo est injustus, aut incauti potius habendi sunt improbi, id. Leg. 1, 14, 40: Quae est ergo ista ratio, aut quae potius ista amentia? id. Verr. 3, 173.
      5. 5. Aut ne … quidem: ego jam aut rem aut ne spem quidem exspecto, Cic. Att. 3, 22 fin.
        Note: Aut regularly precedes the words of its clause, but sometimes in the poets it takes the second place: Saturni aut sacram me tenuisse diem, Tib. 1, 3, 18 Lachm.: justos aut reperire pedes, id. 2, 5, 112: Persequar aut studium linguae etc., Prop. 4, 21, 27: Fer pater, inquit, opem! Tellus aut hisce, vel istam, etc., Ov. M. 1, 545 (Merk., ait): Balteus aut fluxos gemmis adstrinxit amictus, Luc. 2, 362, where some read haud. See more upon this word in Hand, Turs. I. pp. 525-558.