Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

nī̆grefacĭo, ēre, v. a. [1. niger-facio], to make black, to blacken: nigrefacio, μελανοποιῶ, Vet. Gloss.
Pass.: nigrĕfīo, to become black, Theod. Prisc. 1, 5.