Lewis & Short

sŏdālis, is (abl., regularly, sodali; sodale, Mart. 1, 86, 5; Plin. Ep. 2, 13, 6), comm. [cf. Sanscr. svadhā, will, power; Gr. ἔθος, custom; v. Curt. Gr. Etym. p. 251].

  1. I. In gen., a mate, fellow, intimate, comrade, crony, boon-companion, etc. (freq.and class.; a favorite word with Plautus; cf.: socius, familiaris): tuos amicus et sodalis, Plaut. Merc. 2, 4, 7: hic sodalis tuos amicus optimus, id. Cas. 3, 3, 18; so (with amicus) id. Bacch. 3, 3, 71: sodalem me esse scis gnato tuo, id. Most. 5, 2, 32: sex sodales repperi, Vitam, amicitiam, etc., id. Merc. 5, 2, 4: quid enim aut illo fidelius amico aut sodale jucundius? Plin. Ep. 2, 13, 6: si frater aut sodalis esset, Ter. Ad. 4, 5, 74: sodalis et familiarissimus Dolabellae, Lentul. ap. Cic. Fam. 12, 14, 7: primum habui semper sodales. Sodalitates autem me quaestore constitutae sunt sacris Idaeis … epulabar igitur cum sodalibus omnino modice, etc. (shortly after: coetu amicorum), Cic. Sen. 13, 45: popularis et sodalis, id. Ac. 2, 37, 118: meus sodalis, id. de Or. 2, 49, 200: adulescentes aliquot, aequales sodalesque: adulescentium Tarquiniorum, Liv. 2, 3: in urbem reversus sodalibus legi, Plin. Ep. 7, 4, 7: Pompei meorum prime sodalium, Hor. C. 2, 7, 5: gaudentem parvisque sodalibus et lare certo Et ludis, id. Ep. 1, 7, 58: sodalis istius (Verris) in hoc morbo et cupiditate, Cic. Verr. 2, 1, 36, § 91: veterem tutare sodalem, Ov. P. 2, 4, 33: O jucunde sodalis, id. ib. 1, 8, 25: dilectos inter sors prima sodalis, id. Tr. 4, 5, 1.
        1. b. In the poets, adject.: turba sodalis, the band of friends, Ov. R. Am. 586.
          Of things: Hebrus, Hor. C. 1, 25, 19: cratera, id. ib. 3, 18, 6.
  2. II. In partic.
    1. A. A fellow or member of a corporation, society, fraternity, college, etc.: sodales sunt, qui ejusdem collegii sunt, quam Graeci ἑταιρίαν vocant, Dig. 47, 12, 4.
      Of the members of a college of priests: sodales in Lupercis, Cic. Cael. 11, 26: Sodales Titii, Tac. A. 1, 54: Augustales, id. ib. 3, 64; Suet. Claud. 6; id. Galb. 8; Inscr. Orell. 2364 sq.; 1588; 1593; 1611 et saep.
    2. B. In a bad sense, a participator, accomplice in unlawful secret associations (esp. for buying votes, plotting against the State, etc.): quos tu si sodales vocas, officiosam amicitiam nomine inquinas criminoso, Cic. Planc. 19, 46: tu in illis es decem sodalibus: Te in exsilium ire hinc oportet, Plaut. Pers. 4, 4, 12.
      1. 2. A gallant, Mart. 9, 3, 8; Hier. adv. Juv. 1, 48.