darkness vs duskiness

darkness and duskiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
darkness	Yes	No	No	No
duskiness	Yes	No	No	No

As nouns, darkness and duskiness are synonyms defined as:

Other synonyms of darkness include swarthiness.

darkness (noun)	duskiness (noun)
a swarthy complexion	a swarthy complexion
having a dark or somber color	the state of being poorly illuminated
an unenlightened state
an unilluminated area
absence of light or illumination
absence of moral or spiritual values