soberness vs gravity

soberness and gravity both are nouns.

Word	Noun	Adjective	Verb	Adverb
soberness	Yes	No	No	No
gravity	Yes	No	No	No

As nouns, soberness and gravity are synonyms defined as:

Other synonyms of soberness include graveness, sobriety, somberness, sombreness.

soberness (noun)	gravity (noun)
a manner that is serious and solemn	a manner that is serious and solemn
the state of being sober and not intoxicated by alcohol	a solemn and dignified feeling
	(physics) the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface