Lewis & Short

nĕbŭla, ae, f. [like nubes; Sanscr. nabhas; Lat. aër, caelum; Gr. νεφέλη], mist, vapor, fog, smoke, exhalation (syn.: nubes, nimbus).

  1. I. Lit.: fluviis ex omnibus et simul ipsa Surgere de terrā nebulas aestumque videmus, etc., Lucr. 6, 477; Verg. A. 8, 258: tenuem exhalat nebulam, id. G. 2, 217.
    Poet., of the clouds: nebulae pluviique rores, Hor. C. 3, 3, 56; Verg. A. 1, 412; 439 (for which, nubes, id. ib. 587; Ov. M. 6, 21.
    Of smoke, Ov. Tr. 5, 5, 31.
    Of any thing soft or transparent: nebula haud est mollis, atque hujus est, Plaut. Cas. 4, 4, 21: desine Inter ludere virgines Et stellis nebulam spargere candidis, Hor. C. 3, 15, 6.
    Prov.: nebulae cyathus, of any thing worthless, trifling, Plaut. Poen. 1, 2, 62.—
    Personified = Nephele, Hyg. Fab. 2 and 3.
    1. B. Transf., a foggy mist, a vapor, cloud: pulveris nebula, Lucr. 5, 253: nebulae dolia summa tegunt, Ov. F. 5, 269: pinguem nebulam vomuere lucernae, Pers. 5, 181; Sil. 6, 281: per nebulam audire, aut scire aliquid, to hear or know a thing indistinctly, Plaut. Ps. 1, 5, 47; id. Capt. 5, 4, 26 (for which: quasi per caliginem videre, Cic. Phil. 12, 2, 2).
      1. 2. A thin, transparent substance; of a thin garment: aequum est induere nuptam ventum textilem, Palam prostare nudam in nebulā lineā, Laber. ap. Petr. 55; of a thin plate of metal, Mart. 8, 33, 3.
  2. II. Trop., darkness, obscurity: erroris nebula, Juv. 10, 4: nebulae quaestionum, obscure, puzzling questions, Gell. 8, 10 in lemm.: suspicionum nebulae, vague suspicions, Amm. 14, 1, 4.
    Of something empty, trifling, worthless: grande locuturi nebulas Helicone legunto, Pers. 5, 7 (for which: nubes et inania captare, Hor. A. P. 230).