per-dŭellis (noun M) : (
* Gen. plur. perduellūm, Att. ap. Non. 22, 15, or Trag. Rel. p. 238 Rib.; abl. perdvellibus, Enn. ap. Varr. L. L. 7, § 49 Müll., or p. 146 Vahl.), m. per-duellum, i. e. bellum, a public enemy, an enemy actually waging war against a country (mostly anteclass. for the class. hostis): quos nos hostes appellamus, eos veteres perduelles appellabant, per eam adjectionem indicantes, cum quibus bellum esset,Dig. 50, 16, 234: equidem illud etiam animadverto, quod qui proprio nomine perduellis esset, is hostis vocaretur, lenitate verbi tristitiam rei mitigante,Cic. Off. 1, 12, 37; Varr. L. L. 5, § 3 Müll.: apud Ennium perduelles dicuntur hostes,Varr. L. L. 7, § 49 ib.: perduelles superati, S. C. ap. Liv. 45, 16, 7: pirata non est ex perduellium numero, sed communis hostis omnium,Cic. Off. 3, 29, 107; Liv. 25, 12; 36, 2; Plaut. Am. 1, 1, 94; id. Cist. 1, 3, 53; Amm. 26, 7 sq.; 29, 5.
* Transf., a private enemy, an enemy, = inimicus (Plautin.), Plaut. Ps. 2, 1, 8; cf. id. ib. 15.— Perduellis seems never to mean traitor to one's country (cf. perduellio); in this sense parricida is used instead.

s. TLL