Lewis & Short

classis (old orthog. CLASIS, Column. Rostr.; v. under I. B. 2.), is (acc. sing. usu. classem; classim, Auct. B. Afr. 9, 2; abl. usu. classe; classi, Verg. A. 8, 11; Liv. 23, 41, 8; Vell. 2, 79), f. [root cal-, cla-, of clamo, καλέω; prop. the people as assembled or called together], hence,

  1. I. After the division of the Roman people by Servius Tullius into six (or, the citizens who paid tribute alone being reckoned, into five) classes,
      1. 1. A class, Liv. 1, 42, 5; 1, 43, 2 sq.; Cic. Rep. 2, 22, 39 sq.; Gell. 6 (7), 13, 1 sq.; Cic. Fl. 7, 15; Liv. 1, 42, 5; 1, 43, 1 sqq.; Plin. 33, 3, 13, § 43; cf. Dion. Halic. 4, 16 sq.; 7, 59: prima classis vocatur … tum secunda classis, etc., Cic. Phil. 2, 33, 82: infra classem; v. classicus, I.
      2. 2. Trop.: qui (philosophi) mihi cum illo collati, quintae classis videntur, i.e. of the lowest rank, Cic. Ac. 2, 23, 73; cf. classicus, I. B.
        Hence,
    1. B. In milit. lang., the whole body of the citizens called to arms, an army. 1 Of the land army (mostly very ancient): procincta, Lex Numae in Fest. s. v. opima, p. 189, 13 Müll.: classis procincta [id est exercitus armatus, Gloss.], Fab. Pictor. ap. Gell. 10, 15, 4; cf. Gell. 1, 11, 3; Paul. ex Fest. p. 56, 3: classi quoque ad Fidenas pugnatum cum Vejentibus quidam in annales rettulere, Liv. 4, 34, 6 Weissenb. ad loc.: Hortinae classes populique Latini, Verg. A. 7, 716 Serv.
      1. 2. Of men at sea, the fleet, including the troops in it (the usu. signif. in prose and poetry): CLASESQVE. NAVALES. PRIMOS. ORNAVET. … CLASEIS. POENICAS. … , Column. Rostr., v. 7 sq.: nomina in classem dare, Liv. 28, 45, 19: cetera classis … fugerunt, id. 35, 26, 9: ut classem duceret in Ligurum oram, id. 40, 26, 8; 41, 24, 13; cf. id. 42, 48, 10: navium classis, id. 22, 37, 13: posteaquam maximas aedificasset ornassetque classes, Cic. Imp. Pomp. 4, 9: classem instruere atque ornare, id. Verr. 2, 5, 51, § 135: classis ornandae reficiendaeque causā, Liv 9, 30, 4: comparare, Cic. Fl. 14, 33: facere, Caes. B. C. 3, 42 al.: classe navigare, by ship, Cic. Fl. 14, 32; cf. Verg. A. 1, 379; 8, 11; Hor.C. 3, 11, 48: classes = naves, Verg. A. 2, 30: geminasque legit de classe biremis, id. ib. 8, 79: omittere, id. ib. 5, 794: armare, id. ib. 4, 299: deducere, id. G. 1, 255: efficere, Nep. Them. 2, 3: (Suiones) praeter viros armaque classibus valent, Tac. G. 44.
  2. II. In the post-Aug. per., sometimes, a class, division, in gen.: pueros in classes distribuerant, Quint. 1, 2, 23; so id. 1, 2, 24; 10, 5, 21; Suet. Tib. 46: operarum, Col. 1, 9, 7: servorum, Petr. 74, 7.