lightlessness vs total darkness

lightlessness and total darkness both are nouns.

Word	Noun	Adjective	Verb	Adverb
lightlessness	Yes	No	No	No
total darkness	Yes	No	No	No

As nouns, lightlessness and total darkness are synonyms defined as:

Other synonyms of lightlessness include black, blackness, pitch blackness.

lightlessness (noun)	total darkness (noun)
total absence of light	total absence of light