Lewis & Short

possum, pŏtŭi, posse, v. n. irreg. (old forms, potis sum, for possum, Plaut. Poen. 5, 2, 26; id. Curc. 5, 3, 23; so, potis est, id. Ps. 1, 1, 41: potis sunt, for possunt, id. Poen. 1, 2, 17: POTISIT, S. C. de Bacchan.: potisset, for posset, and potisse, for posse, Lucil. ap. Non. 484, 32, and 445, 29: potesse, for posse, very freq., Plaut. Aul. 2, 4, 30; id. Cist. 1, 1, 32; id. Truc. 1, 1, 73; id. Ep. 2, 2, 43; id. Bacch. 3, 6, 30 al.; Lucr. 1, 665; 2, 225; 1010: possiem, Plaut. Bacch. 4, 5, 2; id. Stich. 3, 2, 25: potis sis, id. Poen. 4, 2, 53: potis siem, id. Merc. 2, 2, 59: possies, Enn. ap. Gell. 2, 29 fin., or Sat. v. 38 Vahl.; Plaut. As. 4, 2, 10; id. Aul. 4, 10, 17; id. Most. 2, 2, 34; 3, 2, 147; id. Men. 5, 9, 45: possiet, id. Cist. 1, 3, 37; id. Bacch. 3, 1, 3; id. Most. 1, 1, 13 al.; cf. Brix ad Plaut. Mil. 884; Fleck. Krit. Misc. p. 45 sq.
In pass.: potestur, Enn. ap. Diom. p. 380 P. (Ann. v. 594 Vahl.): Pac. ap. Non. 508, 29; Quadrig. ap. id. 508, 30; Lucr. 3, 1010: poteratur, Cael. ap. Non. 508, 27: possitur, Lex. Servil. p. 59 Haubold; Scaurus ap. Diom. p. 381 P.: possetur, Quadrig. ap. Non. 508, 18) [potis-sum].

  1. I. In gen., to be able, have power; I (thou, he, etc.) can (syn. queo): quantum valeam, quantumque possim, Cic. Fam. 6, 5, 1: consilio, quantum potero, labore plus paene quam potero exeubabo, id. Phil. 6, 7, 18: ut, quoad possem et liceret, a senis latere nunquam discederem, id. Lael. 1, 1: timor igitur ab iis aegritudinem potuit repellere, ratio non poterit? id. Tuse. 3, 27, 66.
    With sup.: Caesari te commendavi et tradidi, ut gravissime diligentissimeque potui, as earnestly and warmly as I possibly could, Cic. Fam. 7, 17, 2: potest fieri, it may be, is possible: potest fieri, ut fallar, id. ib. 13, 73, 2: non possum quin, I can not but: non possum quin exclamem, ut ait ille in Trinummo (Plaut. Trin. 3, 2, 79; cf. id. Mil. 2, 2, 107); Cic. de Or. 2, 10, 39: ut nihil ad te dem litterarum, facere non possum, I cannot help writing to you, id. Att. 8, 14, 1: facere non potui quin tibi sententiam declararem meam, id. Fam. 6, 13, 1; cf.: non possum non: aequitatem tuam non potui non probare, id. ib. 1, 9, 26: non possum te non accusare, id. ib. 5, 14, 2: is non potest eam (mortem) non timere, id. Fin. 3, 8, 29.
    Absol.: potest (sc. fieri), it may be, is possible: potest, ut alii ita arbitrentur, Plaut. Ps. 2, 2, 38: non, non sic futurum est; non potest, Ter. Phorm. 2, 1, 73; Plaut. Mil. 3, 1, 100 Brix; cf. id. Trin. 3, 3, 3: quae (mala) si potest singula consolando levare, etc., Cic. Fin. 5, 28, 84: nos dignitatem, ut potest, retinebimus, id. Fam. 1, 2, 4.
    Quantum or ut potest, as much or as far as possible: ibo atque arcessam medicum, quantum potest, Plaut. Men. 5, 2; id. Most. 3, 2, 71; Ter. Eun. 5, 1, 20: nos in senatu dignitatem nostram, ut potest in tantā hominum perfidiā, retinebimus, Cic. Fam. 1, 2, 4.
    In urgent questions: possum scire, quo profectus, cujus sis, aut quid veneris? may I know? can I learn? pray, will you tell me? Plaut. Am. 1, 1, 190: possumne ego hodie ex te exsculpere Verum? Ter. Eun. 4, 4, 44.
  2. II. In partic.
    1. A. To be able, to have influence or efficacy, to avail.
      1. 1. With neutr. acc. used adverbially (class.; cf. polleo): vocat me, quae in me plus potest, Plaut. Truc. 4, 2, 42: plus potest qui plus valet, id. ib. 4, 3, 38: qui tum et poterant per vim et scelus plurimum, et quod poterant, id audebant, Cic. Quint. 21, 69: quid ergo? hoc pueri possunt, viri non poterunt? id. Tusc. 2, 14, 34: qui apud me et amicitiā, et beneficiis, et dignitate plurimum possunt, id. Rosc. Am. 1, 4: plus aliquanto apud te pecuniae cupiditas, quam judicii metus potuit, id. Verr. 2, 3, 57, § 131; id. de Or. 2, 42, 180: quid aristolochia ad morsus serpentum possit, id. Div. 1, 10, 16: quoniam multum potest provisio animi ad minuendum dolorem, id. Tusc. 3, 14, 30: ad beate vivendum satis posse virtutem, id. ib. 5, 5, 12: multum posse ad salutem alterius … parum potuisse ad exitium, Cic. Opp. ap. Amm. 30, 8, 7.
      2. 2. In gen., and without neutr. acc. (late Lat.): posse litteras ejus ad perniciem, non posse ad salutem, App. Mag. 79, p. 324.
    2. B. Posse aliquem, to be able to embrace one (poet.), Mart. 3, 32.
    3. C. Posse as subst. (poet.): posse loqui, the power of speech, Ov. M. 2, 483: posse moveri = facultatem se movendi, id. ib. 11, 177.
    4. D. Freq. in elliptical sentences: quod vi non poterant, fraude assequi temptant, Curt. 5, 10, 8: Ismenias, etsi publicis non poterat, privatis tamen viribus adjuvabat, Just. 5, 9, 8: ut auxilium quod misericordiā non poterat, jure cognationis obtineret, id. 28, 1, 9: ut collegam vi, si aliter non possent, de foro abducerent, Liv. 2, 56.
    5. E. In apodosis of conditional sentences, analogous to the auxiliaries of the Engl. potential mood (v. Roby, § 1520; Zumpt, § 519).
      1. 1. Indic.: ille potuit exspectatior venire, qui te nuntiaret mortuom (= si quis nuntiaret, etc.), Plaut. Most. 1, 2, 12: nec vero ipsam amicitiam tueri possumus, nisi aeque amicos et nosmet ipsos diligamus, Cic. Fin. 1, 20, 67: Pompeius munitiones Caesaris prohibere non poterat, nisi praelio decertare vellet, Caes. B. C. 3, 44: consul esse qui potui, nisi eum vitae cursum tenuissem, Cic. Rep. 1, 6, 10: (res publica) poterat esse perpetua, si patriis viveretur institutis, id. ib. 3, 29, 41: deleri totus exercitus potuit, si fugientis persecuti victores essent, Liv. 32, 12, 6: nisi felicitas in socordiam vertisset exuere jugum potuerunt, Tac. Agr. 31.
      2. 2. Subj.: qui denique ex bestiis fructus, nisi homines adjuvarent, percipi posset, Cic. Off. 2, 4, 14; cf.: ventum quidem erat eo, ut, si hostem similem antiquis Macedonum regibus habuisset consul, magna clades accipi potuerit, Liv. 44, 4, 9.
        So when the condition is implied, or is contained in an adverbial clause: quae res egestati et aeri alieno tuo praeter mortem Caesaris subvenire potuisset? Cic. Phil. 2, 14, 36: quis opifex praeter naturam … tantam sollertiam persequi potuisset in sensibus? id. N. D. 2, 57, 142; id. Tusc. 4, 19, 44: plurima proferre possemus, sed modus adhibendus est, Nep. Epam. 4, 6: possem hic Ciceronis respondere verbis, sed, etc., Quint. 2, 21, 14.
        Hence, pŏtens, entis (gen. plur. potentum, Verg. A. 12, 519; Claud. Laud. Stil. 2, 114), P. a.
    1. A. In gen., able, mighty, powerful, potent (class.): amplae atque potentes civitates, Cic. Inv. 2, 56, 169: familiae clarae ac potentes, Liv. 23, 4: amici magni et potentes, Suet. Aug. 56: ne quis ex plebe contra potentiorem auxilii egeret, Caes. B. G. 6, 10: duo potentissimi reges, Cic. Imp. Pomp. 2, 4: potentissimus et clarissimus civis, id. Planc. 21, 51.
          1. (β) With gen.: quanta sit humani ingenii vis, quam potens efficiendi quae velit, Quint. 12, 11, 10.
          2. (γ) With abl.: Roma potens opibus, Ov. F. 4, 255: pecuniā et orbitate, Tac. H. 1, 73.
          3. (δ) With inf.: compensare potens, Dig. 16, 2, 10.
    2. B. In partic.
      1. 1. Having power over, ruling over, master of a thing; with gen.: dum liber, dum mei potens sum, as long as I am my own master, Liv. 26, 13, 14: sanus mentisque potens, in his right mind, Ov. Tr. 2, 139: potens mei non eram, Curt. 4, 13, 23: potentes rerum suarum atque urbis, having made themselves masters of, Liv. 23, 16, 6; so, facere aliquem potentem alicujus rei, to make one master of any thing, to give one the power over a thing: consilii, id. 8, 13, 14: imperii, id. 22, 42, 12: diva potens Cypri, that reigns over Cyprus, i.e. Venus, Hor. C. 1, 3, 1: Naïadum potens (Bacchus), id. ib. 3, 25, 14: silvarum potens Diana, id. C. S. 1: diva potens uteri, i.e. Lucina, Ov. M. 9, 315: rerum omnium potens Juppiter, Tac. H. 4, 84: lyrae Musa potens, that presides over lyric poetry, Hor. C. 1, 6, 10: irae, master of his anger, Curt. 4, 2, 5: mariti, ruling her husband, Tac. A. 14, 60: animal potens leti, that can kill, deadly, Luc. 6, 485; cf. id. 5, 199 Corte ad loc.
      2. 2. Fit for, capable of any thing; with gen.: potens regni, Liv. 24, 2: hostes neque pugnae, neque fugae satis potentes caeduntur, unable either to fight or flee, id. 8, 39.
      3. 3. Partaking of, having attained a thing; with gen. (poet.): pacis potentes, Plaut. Poen. 5, 4, 9: voti, Ov. M. 8, 80: jussi, having fulfilled the command, id. ib. 4, 509.
      4. 4. Strong, mighty, powerful, efficacious, potent (mostly poet. and in post-Aug. prose): fortuna in res bellicas potens, Liv. 9, 17: herba potens ad opem, Ov. H. 5, 147: verba, id. Am. 3, 11, 31: herba potens adversus ranas, Plin. 25, 10, 81, § 130: passum ex uvis contra haemorrhoida potens, id. 23, 1, 12, § 15.
        Comp.: nihil esse potentius auro, Ov. Am. 3, 8, 29: quaedam ad efficiendum potentiora, Quint. 6, 1, 26.
        Sup.: potentissimae cantharides, Plin. 29, 4, 30, § 94: argumenta, Quint. 6, 4, 22.
        Hence, adv.: pŏtenter, strongly, mightily, powerfully, effectually (poet. and in post-Aug. prose): se ipsam potenter atque efficaciter defendere, Val. Max. 1, 1, 1: dicere, Quint. 12, 10, 72.
        Comp.: aurum … perrumpere amat saxa potentius Ictu fulmineo, Hor. C. 3, 16, 9; Quint. 6, 4, 18.
    3. B. According to one’s ability or powers (poet.): lecta potenter res, Hor. A. P. 40.