Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
nī̆grēdo, ĭnis, f. [niger], blackness, black color (post-class.): capilli corvinā nigredine, App. M. 2, p. 118, 31: nigredo ollae, Vulg. Nah. 2, 10; Mart. Cap. 2, § 137: atrae noctis, id. 1, § 67.