Lewis & Short

Phlegra, ae, f., = Φλέγρα,

  1. I. a country of Macedonia, afterwards called Pallene, where the giants are fabled to have been struck with lightning when fighting with the gods, Plin. 4, 10, 17, § 36; Stat. Th. 2, 595; Val. Fl. 1, 564; Sen. Herc. Fur. 444.
    As adj.: Phlegra giganteo sparsa est quo sanguine tellus, Verg. Cul. 28.
    Hence,
  2. II. Phlegraeus, a, um, adj., Phlegrœan: Phlegraei campi, Ov. M. 10, 151: tumultus, Prop. 2, 1, 39: castra, Stat. Achill. 1, 484: pugnae, Val. Fl. 5, 693: victoria, Mart. 8, 78, 1.
    1. B. Transf.
      1. 1. Campi, a plain abounding in sulphur, between Puteoli and Naples, the modern Solfatara, Plin. 3, 5, 9, § 61; Sil. 8, 540: vertex, i. e. the volcano of Vesuvius, Sil. 8, 657.
      2. 2. Poet., of a bloody battle: campus, i. e. Pharsalus, Prop. 3, 11 (4, 10), 37.