Lewis & Short

tertĭus, a, um, num. ord. adj. [ter], the third.

  1. I. Adj.: vos duo eritis, atque amica tua erit tecum tertia, Plaut. Bacch. 4, 4, 66: tres video sententias ferri: unam, etc. … alteram, etc. … tertiam ut, etc., Cic. Lael. 16, 56; cf. Caes. B. G. 1, 1; Varr. R. R. 1, 2, 26: sic disserunt: si quod sit in obscenitate flagitium, id aut in re esse aut in verbo: nihil esse tertium, Cic. Fam. 9, 22, 1; cf. id. Phil. 2, 13, 31: annus, id. Rep. 2, 37, 62: tertio illo anno, id. ib. 3, 32, 44: mancipia venibant Saturnalibus tertiis, i.e. on the third day of the Saturnalia, id. Att. 5, 20, 5: ab Jove tertius Ajax, the third in descent, greatgrandson of Jupiter, Ov. M. 13, 28: per tertia numina juro, i.e. by the infernal gods, id. Tr. 2, 53: regna, the infernal regions, id. F. 4, 584: tertius e nobis, i.e. one of us three, id. M. 14, 237: tertios creari (censores), Liv. 6, 27, 5: tertius dies est, it is two days since, Plin. Ep. 4, 27, 1: syllaba ab eā tertia, Quint. 1, 5, 30: diebus tertiis, every three days, Gell. 9, 4, 7.
  2. II. Substt.
    1. A. tertĭae, ārum, f. (sc. partes).
      1. 1. A third part: miscentur argento tertiae aeris Cyprii, Plin. 33, 9, 46, § 131; 34, 5, 11, § 20: cum ad tertias subsederit coctura, Col. 12, 20, 4; 12, 35; Plin. 21, 18, 71, § 119: duae tertiae partes, two thirds, Col. 5, 2, 11.
      2. * 2. The third part in a play: Spinther secundarum, tertiarumque Pamphilus, Plin. 7, 12, 10, § 54.
    2. B. Tertĭus, ii, m., and Tertĭa, ae, f., proper names. The latter in a sarcastic pun: Tertiā deductā (after a third was deducted, or after Tertia was seduced), Cic. ap. Macr. S. 2, 2; Suet. Caes. 50.
      Adv.
    1. A. tertĭō.
      1. 1. For the third time: non hercle veniam tertio, Ter. Eun. 3, 3, 24: ille iterum, ille tertio pecuniam dedit, Cic. Deiot. 5, 14: sanguis mittendus est iterum tertioque, Cels. 4, 4, fin.: cui ter proditae patriae: semel cum, etc. … iterum cum, etc. … tertio hodie, etc., Liv. 23, 9, 11; tertio consules esse, Plin. Pan. 60, 5; cf. Gell. 10, 1.
      2. * 2. In the third place, thirdly: haec spectans, etc. … simul, ut, etc. … tertio, ut, etc., Caes. B. C. 3, 43.
      3. 3. Three times (post-class.): parietes tertio obducere, Pall. 1, 11, 2; Treb. Gall. 17.
    2. B. tertĭum, for the third time: nemo est quin saepe jactans Venerium jaciat aliquando, non numquam etiam iterum ac tertium, Cic. Div. 2, 59, 121: veniunt iterum atque tertium, Cato ap. Charis. p. 196 P.: idque iterum tertiumque, Plin. 14, 22, 28, § 139: consules creati Q. Fabius Vibulanus tertium et L. Cornelius Maluginensis, Liv. 3, 22, 1; 6, 27, 2: mori consulem tertium oportuit, id. 3, 67, 3; Front. Aquaed. 10; cf. Gell. 10, 1.