Lewis & Short

lūgū̆bris (lūgūbris, Lucr. 4, 547), e, adj. [lugeo and fero], of or belonging to mourning, mourning-.

  1. I. Lit.: lamentatio, over the dead, Cic. Tusc. 1, 13, 30: vestis, mourning apparel, Ter. Heaut. 2, 3, 45; cf. cultus, Tac. A. 13, 32: cantus, a dirge, Hor. C. 1, 24, 2: domus, a house of mourning, Liv. 3, 32: genitor, mourning, sorrowing, Ov. M. 4, 690; so, pectora, id. H. 10, 145.
    Subst.: lūgū̆brĭa, ĭum, n., mourning garments, sable weeds: lugubria indue, Ov. M. 11, 669; illa dies veniet, mea qua lugubria ponam. id. Tr. 4, 2, 73: imposita lugubria numquam exuerunt, Sen. Cons. ad Helv. 16, 2: lugubria sumpsi, Prop. 4 (5), 12, 97.
  2. II. Transf.
    1. A. That causes mourning, disastrous: bellum, Hor. C. 2, 1, 33: Trojae renascens alite lugubri, id. ib. 3, 3, 61.
    2. B. Mournful, doleful, plaintive: vox, Lucr. 4, 546: vagitus, id. 5, 226: verba, Ov. Ib. 99.
    3. C. Mean, pitiable: sagum, Hor. Epod. 9, 28.
      Hence, adv., in two forms: lūgū̆bre and lūgū̆brĭter, mournfully, dolefully, portentously, plaintively: cometae Sanguinei lugubre rubent, Verg. A. 10, 273: sonitu lugubre minaci Mulciber immugit, Sil. 12, 140: lugubriter eiulantes, App. M. 3, 8, p. 132.