Lewis & Short

austērĭtas, ātis, f. [austerus] (perh. not before the Aug. period).

  1. I. Lit.
    1. A. Of taste, harshness, sourness (syn.: acerbitas, tristitia, severitas), Col. 11, 2, 68: vini, Plin. 14, 2, 4, § 24; 14, 6, 8, § 65: caepae, id. 19, 6, 32, § 105: picis, id. 14, 1, 3, § 17; Pall. 1, 35, 11; and in plur., id. 1, 35, 8.
    2. B. Of colors, darkness, dinginess, Plin. 35, 10, 36, § 97; 9, 38, 62, § 134; 35, 10, 36, § 97; 35, 11, 40, § 134.
  2. II. Trop., severity, austerity, rigor: magistri, Quint. 2, 2, 5: qui a te hanc austeritatem exigo, Plin. Ep. 2, 5, 5: cum austeritate imperare, Vulg. Ezech. 34, 4: ex bono esse austeritatem, ib. 2 Macc. 14, 30.