darkness vs swarthiness

darkness and swarthiness both are nouns.

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

As nouns, darkness and swarthiness are synonyms defined as:

Other synonyms of darkness include duskiness.

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