darkening

nouns

changing to a darker color
blackening, darkening
is derived from
darken
is derived from
darken

adjectives

becoming dark or darker as from waning light or clouding over
"the darkening sky"
darkening
is similar to
devoid of or deficient in light or brightness; shadowed or black
"sitting in a dark corner"; "a dark day"; "dark shadows"; "dark as the inside of a black cat"
dark