Defn: The complex, nitrogenous, organic base and dyestuff called also aniline black.

NIGRESCENT Ni*gres"cent, a. Etym: [L. nigrescens, p.pr. of nigrescere to grow black, fr. niger black. See Negro.]

Defn: Growing black; changing to a black color; approaching to blackness. Johnson.

NIGRIFICATION Nig`ri*fi*ca"tion, n. Etym: [L. nigrificare to blacken; niger black + -ficare (in comp.) to make. See -fy.]

Defn: The act or process of making black. [R.] Johnson.

NIGRINE
Ni"grine, n. Etym: [L. niger black: cf. F. nigrine.] (Min.)

Defn: A ferruginous variety of rutile.

NIGRITIC
Ni*grit"ic, a. (Ethnol.)

Defn: Pertaining to, or having the characteristics of, negroes, or of the Negritos, Papuans, and the Melanesian races; negritic.

NIGRITUDE
Nig"ri*tude, n. Etym: [L. nigritudo, fr. niger black.]