tenuity vs low density

tenuity and low density both are nouns.

Word	Noun	Adjective	Verb	Adverb
tenuity	Yes	No	No	No
low density	Yes	No	No	No

As nouns, tenuity and low density are synonyms defined as:

Other synonyms of tenuity include rarity.

tenuity (noun)	low density (noun)
a rarified quality	a rarified quality
the quality of lacking intensity or substance
relatively small dimension through an object as opposed to its length or width