incessantness vs endlessness

incessantness and endlessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
incessantness	Yes	No	No	No
endlessness	Yes	No	No	No

As nouns, endlessness is a hypernym of incessantness; that is, endlessness is a word with a broader meaning than incessantness:

incessantness: the quality of something that continues without end or interruption
endlessness: the property of being (or seeming to be) without end

incessantness (noun)	endlessness (noun)
the quality of something that continues without end or interruption	the property of being (or seeming to be) without end