Lewis & Short

princĭpālis, e, adj. [princeps].

  1. I. In gen., first, original, primitive (class.): causae, Cic. Fat. 5, 9: est igitur tropus sermo a naturali et principali significatione translatus ad aliam, Quint. 9, 1, 4: verba, Gell. 11, 15, 5.
  2. II. In partic.
    1. A. In rank, first in rank, station, or esteem, chief, principal: viri, App. Flor. p. 363, 38.
      Of things abstr. and concr.: pici principales in auguriis, Plin. 10, 18, 20, § 41: principalia in Arabiā tus, et myrrha, id. 12, 13, 30, § 51: principalia aquatilium, id. 31, 6, 38, § 72: causarum aliae sunt perfectae et principales, aliae adjuvantes et proximae, Cic. Fat. 18, 41: quaestio, Quint. 4, 4, 1: post haec duo principalia subjungebat illa non minus intuenda, after these two principal points, Col. 1, 3, 3: principali studio (i. e. praecipuo), Gell. 13, 10, 1: principalia verba, primitive, id. 11, 15, 5: de culturā agri praecipere, principale fuit et apud exteros, a principal thing, Plin. 18, 3, 5, § 22: principalis obligatio, res (opp. accessio), Gai. Inst. 3, 126.
      Comp.: principalior, Tert. Anim. 43: principaliora quaeque, id. cont. Marc. 4, 36.
      As subst.: princĭpālis, is, m.
        1. a. The foremost, overseer, superintendent: officiorum, i. e. of attendants, Cod. Just. 9, 51, 1.
        2. b. The chief magistrate of a municipality, Symm. Ep. 9, 1; Dig. 48, 19, 27; Isid. Orig. 9, 4: principalis aut decurio, Cod. Just. 10, 31, 33; 10, 34, 2, § 1.
        3. c. An inferior officer, Dig. 49, 16, 13.
      1. 2. Of or belonging to a prince or ruler, princely, imperial, the emperor’s (post-Aug.): principalis quies, Vell. 2, 56, 3: fastigium, id. 1, 11, 6: opera, id. 2, 124, 3: curae, Plin. Pan. 79: copiae, id. ib. 82: apparatus arrogantiae principalis, id. ib. 76: beneficia, id. ib. 36: matrimonium, Tac. H. 1, 22: commentarii, id. ib. 4, 40: fortuna, id. ib. 2, 81: scortum, id. ib. 1, 13: majestas, Suet. Claud. 17: res, id. Calig. 39: bonum, Plin. 13, 3, 4, § 22: vox, Just. Inst. prooem. 3.
    2. B. Of or belonging to the principes, i. e. to the second line in the order of battle (post-class.), Cod. Th. 12, 1, 151; Veg. Mil. 2, 15, 1.
      1. 2. Of or belonging to the principium in a camp: principalis castrorum porta nominatur, quod in eo loco est, in quo principes ordines tendunt, Paul. ex Fest. p. 224 Müll.: manipulos legionum principali viā inducit, Liv. 10, 33: porta principalis dextra, id. 4, 19; cf. id. 40, 27.
        Adv.: princĭpālĭter.
    1. A. In gen., chiefly, principally (post-class.): plurimae bestiae, sed principaliter leones, Sol. 27: negotium gerere, Dig. 3, 2, 4.
    2. B. In partic., like a prince, imperially (post-Aug.): gaudere, Sen. Cons. ad Polyb. 36: mores juventutis quam principaliter formas! Plin. Pan. 47: institutae leges, Arn. 1, 2, 2: non principaliter, incidentally, Mos. et Rom. Leg. Coll. 12, 7, 5.