Lewis & Short

tristĭtĭa, ae, f. [tristis], sadness, mournfulness, sorrow, grief, melancholy, gloominess, dejection (class.; syn. maestitia).

  1. I. In gen.
    1. A. Of living beings: tum ad tristitiam, tum ad laetitiam est contorquendus, Cic. de Or. 2, 17, 72: ex summā laetitiā atque lasciviā repente omnes tristitia invasit, Sall. C. 31, 1: in eādem tristitiā permanere, Caes. B. G. 1, 32: magno metu ac tristitiā sollicitari, Auct. B. Afr. 10: lacrimis ac tristitiā te tradidisti, Luccei. ap. Cic. Fam. 5, 14, 2: tu sapiens finire memento Tristitiam, Hor. C. 1, 7, 18: tristitiam compescere, Ov. M. 9, 397: esse aliquam cognatam tristitiae voluptatem, Sen. Ep. 99, 25: (vino) tristitia et cura hebetatur, Plin. 23, 1, 22, § 38: tristitiam animi resolvi, id. 24, 6, 15, § 24: subitā tristitiā implicatis militum animis, Val. Max. 1, 6, 12: cum tristitiā et maerore in vitā remanere, id. 2, 6, 14: tristitiam ad ultimam perductus, Petr. 24.
      Trop.: sol recedens quasi tristitiā quādam contrahit terram, Cic. N. D. 2, 40, 102.
    2. B. Of things: haec tristitia temporum, this sad state of the times, Cic. Att. 12, 40, 3: caeli, Plin. 2, 6, 4, § 13: indurata soli, id. 18, 21, 50, § 184: aspectus, id. 9, 9, 11, § 34: lenitate verbi rei tristitiam mitigare, hardness, harshness, Cic. Off. 1, 12, 37.
  2. II. In partic., of demeanor, moroseness, sourness, gloominess, harshness, sternness, severity, etc. (syn. severitas): an nova tristitiae causa puella tuae? Prop. 1, 18, 10: simque ego tristitiae causa modusque tuae, Ov. H. 3, 90: (risus) tristitiam ac severitatem mitigat, relaxat, Cic. de Or. 2, 58, 236; cf. id. Lael. 18, 66: illorum (philosophorum) tristitiam atque asperitatem fugiens, id. Fin. 4, 28, 79: quod ille vos tristitiā vultuque deceperit, id. Prov. Cons. 5, 12; so Quint. Inst. prooem. § 15: non conveniant barbae illi atque tristitiae, id. ib. 11, 1, 34; Plin. Ep. 1, 10, 7; 8, 21, 1; Suet. Ner. 23; Sil. 8, 612.