As nouns the difference between blackening and nigrescence
is that blackening is the act of turning black in colour; a black stain or mark while nigrescence is the process of becoming black or dark; blackening.
As a verb blackening
is (blacken).
blackening
English
Verb
(head)
Noun
(
en noun)
The act of turning black in colour; a black stain or mark.
nigrescence
English
Noun
(nigrescences)
The process of becoming black or dark; blackening.
A dark complexion.