Lewis & Short

pā̆trōnus, i, m. [pater].

  1. I. Lit., a protector, defender, patron (of individuals, or of cities and entire provinces; also, the former master of a freedman); PATRONVS SI CLIENTI FRAVDEM FECERIT SACER ESTO, Fragm. XII. Tab. ap. Serv. Verg. A. 6, 609; quot enim clientes circa singulos fuistis patronos, tot nunc, etc., Liv 6, 18, 6: ego me patronum profiteor plebis, id. 6, 18, 14; civitatum et nationum, Cic. Off. 1, 11, 35; id. Pis. 11, 25; cf.: tum conventus ille Capuae, qui me unum patronum adoptavit, etc., id. Sest. 4, 9; Inscr. A. U. C. 742, Marin. Fratr Arv. p. 782; see also Inscr. Orell. 956; 1079; 3056 sq.: patronus, defensor, custos coloniae, Cic. Sull. 21, 60; id. Div. in Caecil. 1, 2.
    Of the former master of a freedman or freedwoman: volo me placere Philolachi, meo patrono, Plaut. Most. 1, 3, 11: civis Romani liberti hereditatem Lex XII. Tabularum patrono defert, si intestato sine suo herede libertus decesserit, Ulp. Fragm. tit. 29, § 1; cf. Gai. Inst. 3, 40; Cic. Fam. 13, 21, 2: corrupti in dominos servi, in patronos liberti, Tac. H. 2, 2.
  2. II. Transf., a defender before a court of justice, an advocate, pleader (syn.: advocatus, causidicus, procurator, cognitor): judicis est semper in causis verum sequi, patroni nonnumquam verisimile, etiamsi minus sit verum, defendere, Cic. Off. 2, 14, 51; id. de Or. 2, 69, 280: patronus alicui causae constitui, id. Mur. 2, 4; cf.: his de causis ego huic causae patronus exstiti, id. Rosc. Am. 2, 5; Lex. Servil. lin. 9: patronus partis adversae, Quint. 4, 1, 11; cf.: patronus adversarii, id. 4, 1, 11; Tac. Or. 1.
    1. B. In gen., a defender, advocate: eam legem a vestrorum commodorum patrono esse conscriptam, Cic. Agr. 3, 1, 3: foederum ac foederatorum, id. Balb. 10, 25: justitiae, id. Lael. 7 fin.: qui modo patronus nunc cupit esse cliens, Ov. A. A. 1, 88.
      Comically: video ego te, propter malefacta qui es patronus parieti, i. e. standing like a patron in front of the wall (of one who, for fear of blows, places himself with his back to the wall, Plaut. Truc. 4, 3, 48; cf. id. Ps. 2, 2, 12.
      As an affectionate and respectful form of address: mi patrone, immo potius mi pater, Plaut. Rud. 4, 8, 2; 16.