Lewis & Short

sĕvērĭtas, ātis, f. [1. severus],

  1. I. seriousness, gravity, sternness, strictness, severity, in a good and bad sense (class. and very freq.; syn. gravitas): tristis severitas inest in vultu, Ter. And. 5, 2, 16: severitatem in senectute probo: acerbitatem nullo modo, Cic. Sen. 18, 65 (opp. lepos); id. Off. 1, 37, 134: censorum, id. Rep. 4, 6, 15; cf. Val. Max. 2, 9.
    Plur.: censorum severitates, Gell. 4, 20, 1: tristitia et in omni re severitas, Cic. Lael. 18, 66; cf.: homo ipsā tristitiā et severitate popularis, id. Brut. 25, 97: si illius comitatem et facilitatem tuae gravitati severitatique asperseris, id. Mur. 31, 66; so (opp. comitas) id. Brut. 40, 148; (opp. mansuetudo et misericordia) Sall. C. 54, 2; (opp hilaritas risusque) Cic. Brut. 93, 322: T. Torquatus cum illam severitatem in eo filio adhibuit, quem, etc., id. Fin. 1, 7, 24: evellere se aculeum severitatis vestrae, id. Clu. 55, 152: laetissimae vir severitatis, Vell. 2, 127, 4: Catoni severitas dignitatem addiderat, Sall. C. 54, 2: commodare magnis peccatis severitatem, Tac. Agr. 19: summa severitas animadversionis, Cic. Fam. 9, 14, 7: exempli, id. Verr. 2, 5, 3, § 7: judiciorum (opp. lenitas ac misericordia), id. Sull. 33, 92: imperii, Caes. B. G. 7, 4; cf.: militarem disciplinam severitatemque minuere, Auct. B. Alex. 48 fin.; 65: nimia emendationis severitas, Quint. 2, 4, 10: disciplinae, id. 2, 2, 4: orationis, Plin. Ep. 2, 5, 6: hac severitate aurium laetor, this severity of taste, id. ib. 3, 18, 9.
  2. II. Transf.: etiam corruptissimo in genere magis tamen juvat quaedam ipsius viti severitas, rudeness, crudeness, Plin. 13, 3, 4, § 21.