Nigro, nigras, nigrâre. To make blacke.Nigrare. Lucret. To be blacke.
Nigror, nigrôris, m. g. Idem. Cic.
Lewis and Short: Latin dictionary
nīgro, āvi, ātum, 1, v. n. and a. [id.]. I.Neutr., to be black: ea, quae nigrant nigro de semine nata, Lucr. 2, 733.—II.Act., to make black, to blacken. A.Lit.: mgrāsset sibi planctu lacertos, Stat. S. 2, 6, 83.—B.Trop., to make dark, to darken: nigrati ignorantiae tenebris, Tert. adv. Marc. 4, 8.—Hence, nīgrans, antis, P. a., black, dark-colored, dusky: nigrantia boum cornua, Varr R. R. 2, 5: nigrantes terga juvenci, Verg. A. 5, 97: nigrantes alae, Ov. M. 2, 535: nigrantes domos ammarum intrāsse silentūm, Prop. 3, 12, 33 (4, 11, 33): nigrante profundo,
the sea
, Sil. 17, 258: litora, Val. Fl. 4, 697: aegis, i. e.