thinness vs spareness

thinness and spareness both are nouns.

Word	Noun	Adjective	Verb	Adverb
thinness	Yes	No	No	No
spareness	Yes	No	No	No

As nouns, thinness and spareness are synonyms defined as:

Other synonyms of thinness include leanness.

As nouns, thinness and spareness are synonyms defined as:

thinness and spareness: the property of being scanty or scattered; lacking denseness

Other synonyms of thinness include sparseness, sparsity.

thinness (noun)	spareness (noun)
the property of having little body fat	the property of being scanty or scattered; lacking denseness
relatively small dimension through an object as opposed to its length or width	the property of having little body fat
a consistency of low viscosity
the property of being very narrow or thin
the property of being scanty or scattered; lacking denseness
The property of lacking substance or strength.