nigrescence

n. 变黑, 黑色

形容词:nigrescent 

ni.gres.cence

n.（名词）
The process of becoming black or dark.
变黑：变黑或变暗的过程
Blackness or darkness, as of complexion.
肤色的黝黑

来源：
From nigrescent [blackish]
源自 nigrescent [黑的]
from Latin nigrôscôns nigrôscent- [present participle of] nigrôscere [to become black]
源自 拉丁语 nigrôscôns nigrôscent- [] nigrôscere的现在分词 [变黑]
from niger nigr- [black]
源自 niger nigr- [黑]

【引伸】
nigres.cent
adj.（形容词）