Lewis & Short

contentĭo, ōnis, f. [contendo] (acc. to contendo, II.), an eager stretching, a straining, exertion of the powers of body or mind, tension, effort, a vigorous struggling or striving for something, a struggle after (very freq. and in good prose).

  1. I. In gen.
    1. A. Prop.: contentio et summissio vocis, Cic. Off. 1, 41, 146; id. de Or. 1, 61, 261: vocis, id. Tusc. 2, 24, 56: vocis aut lateris, Plin. 26, 13, 85, § 137 al.: gravitatis et ponderum, of gravitation, Cic. N. D. 2, 45, 116: animi (opp. relaxatio), id. de Or. 2, 5, 21; cf. id. Arch. 6, 12 et saep.
      With gen. of the object: disputationis, Cic. de Or. 3, 61, 230: honorum (with ambitio), id. Off. 1, 25, 87; cf. palmae, Quint. 1, 2, 24: dignitatis, id. 4, 5, 12; cf.: libertatis dignitatisque, Liv. 4, 6, 11 al.
    2. B. Transf.
      1. 1. Labored, formal speech (opp. talk, conversation): quoniam magna vis orationis est, eaque duplex, altera contentionis, altera sermonis; contentio disceptationibus tribuatur judiciorum … sermo in circulis, etc., Cic. Off. 1, 37, 132; 2, 14, 48 Heine ad loc.; cf.: sermo est oratio remissa et finitima cottidianae locutioni; contentio est oratio acris, etc., Auct. Her. 3, 13, 23.
      2. * 2. Gregum = admissura, Censor. 5.
  2. II. In partic.
    1. A. (Acc. to contendo, II. B. 2.) A contest, contention, strife (with weapons or words), a fight, dispute, controversy (so most freq.): contentiones proeliorum, Cic. Off. 1, 26, 90; cf.: magna belli, id. Sest. 27, 58: contentiones, quae cum inimicissimis fiunt, id. Off. 1, 38, 137; so with cum, id. Phil. 2, 3, 7; id. Leg. 3, 11, 25 al.: cum aliquo de aliquā re, Quint. 4, 2, 132: de aliquā re, Cic. Leg. 3, 10, 24; Liv. 4, 6, 4; Quint. 5, 14, 12 al.: adversus procuratores, Tac. Agr. 9: inter aliquos, Cic. Sest. 21, 47; Quint. 10, 1, 47; Suet. Claud. 15 et saep.; cf.: inter aliquos de aliquā re, Cic. Ac. 2, 43, 132 et saep.: contentionis cupidiores quam veritatis, id. de Or. 1, 11, 47; Curt. 8, 4, 33.
    2. B. (Acc. to contendo, II. B. 3.) A comparison, contrast: si contentio quaedam et comparatio fiat, Cic. Off. 1, 17, 57; 1, 43, 152; cf. id. Inv. 1, 12, 17: quaedam hominum ipsorum, id. Planc. 2, 5; id. Inv. 2, 39, 114: fortunarum, id. Pis. 22, 51.
      Hence,
      1. 2. T. t.
        1. a. In rhetoric, a contrasting of one thought with another, antithesis, Auct. Her. 4, 15, 21; Cic. de Or. 3, 53, 203; Quint. 9, 1, 31; 9, 2, 2.
        2. b. In gram., comparison, Varr. L. L. 8, § 75 Müll.