Lewis & Short

persĕvēro, āvi, ātum, 1, v. n. and a. [perseverus].

  1. I. Neutr., to abide by or adhere to strictly; to continue steadfastly, to persist, persevere in any thing (class.; syn.: persisto, permaneo).
          1. (α) With in and abl.: perseveras tu quidem et in tuā vetere sententiā permanes, Cic. Leg. 3, 11, 26; so, in suā sententiā, id. Phil. 4, 4, 11: in vitiis, id. Inv. 2, 2, 5: in errore, id. Phil. 12, 2, 5: in eo perseveravit, jus publicano non dicere, id. Prov. Cons. 5, 10; Vulg. Matt. 10, 22; id. Heb. 12, 7: nobiscum, continuing with us, id. Act. 27, 2.
          2. (β) Impers. pass.: perseveratum in irā est, Liv. 2, 35; Cic. Verr. 2, 4, 39, § 85: in eo perseverandum putabat, Caes. B. C. 1, 26, 2.
  2. II. Act., to go on or proceed with steadily, to persist, persevere in any thing (class.); usually constr with an object-clause; rarely with acc. or abl.
          1. (α) With inf.: injuriam facere, Cic. Quint. 8, 31: aliquem conservare, Curius ap. Cic. Fam. 7, 29, 1: bello persequi, Caes. B. G. 1, 13, 4.
            With acc. and inf: cum Orestes perseveraret, se esse Orestem, stuck to it, Cic. Lael. 7, 24; so, cum id facturos se perseverarent, Vell. 2, 92, 3.
          2. (β) With acc.: neque te ipsum id perseverare et transigere potuisse, Cic. Quint. 24, 76: religiosam observantiam, Symm. Ep. 1, 90 (96).
            In the pass.: ob haec illi quatriduo perseverata inedia est, Just. 12, 6, 15
          3. (γ) With abl.: bellis continuis perseverare, Just. 38, 4, 11.
            Hence, persĕvērans, antis, P. a., persevering; with abl.: perseverantior caedendis (hostibus), Liv. 5, 31, 4 (Madv. caedendi).
            Absol.: perseverantissimus sui cultus, Val. Max. 6, 6, 1 ext.: perseverantissimum studium, Col. praef. 1, § 19: pertinaciter perseverans, Jul. Obseq. 64: valetudo, Plin. Ep. 1, 12, 9: perseverantissima pietas, Aug. Ep. 555.
            Adv.: persĕvēranter, perseveringly: tueri, Liv. 4, 60, 5: tacere, Val. Max. 6, 1, 7.
            Comp.: perseverantius saevire, Liv. 21, 10, 7.
            Sup.: aliquem perseverantissime diligere, Plin. Ep. 4, 21, 3 (dub.; Keil, persevera).