Lewis & Short

flā̆gro, āvi, ātum, 1, v. n. [root in Sanscr. brag-, to glow; Gr. φλέγω, φλεγέθω, φλόξ; Lat. fulgeo, fulgur, fulmen, flamma, flamen, fulvus; Angl.-Sax. blāc, pale; Germ. bleich; connected with flagito, flagitium, etc., by Corss. Ausspr. 1, 398], to flame, blaze, burn (class.; trop. signif. most freq.; not in Caes.; syn.: ardeo, deflagro, caleo, ferveo, etc.).

  1. I. Lit.: flagrantes onerariae, Cic. Div. 1, 32, 69: crinemque flagrantem excutere, Verg. A. 2, 685: flagrabant ignes, Ov. F. 6, 439: intima pars hominum vero flagrabat ad ossa, Lucr. 6, 1168: flocci molles et sine oleo flagrant, Plin. 16, 7, 10, § 28: ut flagret (carbo), id. 33, 13, 57, § 163.
  2. II. Trop., sc. according as the notion of heat or of the pain produced by burning predominates (cf. flamma, II.).
    1. A. To be inflamed with passion (in a good and a bad sense), to blaze, glow, burn, be on fire, to be violently excited, stirred, provoked.
      With abl.: non dici potest, quam flagrem desiderio urbis, Cic. Att. 5, 11, 1; so, desiderio tui, id. ib. 7, 4, 1: dicendi studio, id. de Or. 1, 4, 14; cf.: eximio litterarum amore, Quint. prooem. § 6: mirabili pugnandi cupiditate, Nep. Milt. 5, 1: cupiditate atque amentia, Cic. Verr. 2, 4, 34, § 75; cf. id. Clu. 5, 12: amore, id. Tusc. 4, 33, 71; Hor. Epod. 5, 81; cf.: cupidine currus, Ov. M. 2, 104: libidinibus in mulieres, Suet. Gramm. 23: odio, Cic. de Or. 2, 45, 190: totam Italiam flagraturam bello intelligo, id. Att. 7, 17, 4: bello flagrans Italia, id. de Or. 3, 2, 8: convivia quae domesticis stupris flagitiisque flagrabunt, id. Verr. 2, 4, 32, § 71.
      Absol.: flagrabant vitia libidinis apud illum, id. Cael. 5, 12; cf.: uti cujusque studium ex aetate flagrabat, Sall. C. 14, 6.
      Poet. with acc. of respect, to love: caelestem flagrans amor Herculis Heben, Prop. 1, 13, 23: Cerberus et diris flagrat latratibus ora, Verg. Cul. 220.
      1. * 2. Poet. as a v. a., to inflame with passion: Elisam, Stat. S. 5, 2, 120.
    2. B. To be greatly disturbed, annoyed, vexed; to suffer: consules flagrant infamiā, Cic. Att. 4, 18, 2; cf.: invidiā et infamiā, id. Verr. 1, 2, 5: invidiā, id. Clu. 49, 136; id. Sest. 67, 140: Tac. A. 13, 4; Plin. Ep. 9, 13, 21; Suet. Aug. 27; id. Galb. 16: infamiā, id. Caes. 52; id. Tib. 44: rumore malo, Hor. S. 1, 4, 125; ignominiā et pudore, Flor. 2, 18: inopiā et cupidinibus, Sall. Or. Philipp. p. 220 ed. Gerl.
      Hence, flā̆grans, antis, P. a., flaming, blazing, burning, glowing.
    1. A. Lit.: fulmen, Varr. Atacin. ap. Quint. 1, 5, 18; cf. telum, Verg. G. 1, 331: flagrantis hora Caniculae, Hor. C. 3, 13, 9; cf.: flagrantissimo aestu, Liv. 44, 36, 7: genae, Verg. A. 12, 65: oscula, Hor. C. 2, 12, 25.
      1. 2. Transf., of color, glittering, shining: (Aeneas) Sidereo flagrans clipeo et caelestibus armis, Verg. A. 12, 167: redditur extemplo flagrantior aethere lampas (i. e. sol), Sil. 12, 731.
    2. B. Trop., glowing with passion, ardent, eager, vehement: oratoria studia quibus etiam te incendi, quamquam flagrantissimum acceperam, Cic. Fat. 2, 3: non mediocris orator, sed et ingenio peracri et studio flagranti, id. de Or. 3, 61, 230: recentibus praeceptorum studiis flagrans, id. Mur. 31, 65: flagrans, odiosa, loquacula, Lampadium fit, flickering, restless, Lucr. 4, 1165: in suis studiis flagrans cupiditas, Cic. Tusc. 4, 19, 44: flagrantissima flagitia, adulteria, Tac. A. 14, 51: flagrantissimus amor, Plin. Ep. 6, 8, 2: Nero flagrantior in dies amore Poppaeae, Tac. A. 14, 1; id. H. 4, 39: Othonis flagrantissimae libidines, id. ib. 2, 31; Val. Max. 8, 14 ext. 3: studia plebis, Tac. A. 2, 41 fin.: aeger et flagrans animus, id. ib. 3, 54: flagrantior aequo Non debet dolor esse viri, Juv. 13, 11: adhuc flagranti crimine comprehensi, i. e. in the very act, Cod. Just. 9, 13, 1.
      Hence, flā̆gran-ter, adv., ardently, vehemently, eagerly (post-Aug.): Germani exarsere flagrantius, Amm. 31, 10, 5: flagrantius amare, Fronto, Ep. ad Anton. 2 ed. Mai.: flagrantissime cupĕre, Tac. A. 1, 3.