bottomlessness vs deepness

bottomlessness and deepness both are nouns.

Word	Noun	Adjective	Verb	Adverb
bottomlessness	Yes	No	No	No
deepness	Yes	No	No	No

As nouns, deepness is a hypernym of bottomlessness; that is, deepness is a word with a broader meaning than bottomlessness:

Other hypernyms of bottomlessness include profoundness, profundity.

bottomlessness (noun)	deepness (noun)
the property of being very deep; without limit	the quality of being physically deep
	the extent downward or backward or inward
	a low pitch that is loud and voluminous
	the intellectual ability to penetrate deeply into ideas