furvescens
furvescens, entis, Part. [furvus],
- growing dark, dusky (late Lat.): Tartareae noctis obscuritate furvescens, Mart. Cap. 1, § 30.
fūrvēscēns, tis (furvus), dunkelnd, Mart. Cap. 1. § 30.
furvēscēns, tis (fursus), qui sʼobscurcit : Capel. 1, 30.