overreaching vs vaulting

overreaching is not a noun while vaulting is a noun.

Word	Noun	Adjective	Verb	Adverb
overreaching	No	Yes	No	No
vaulting	Yes	Yes	No	No

As adjectives, overreaching and vaulting are synonyms defined as:

overreaching and vaulting: revealing excessive self-confidence; reaching for the heights

overreaching (noun)	vaulting (noun)
	a light leap by a horse in which both hind legs leave the ground before the forelegs come down
	(architecture) a vaulted structure

overreaching (adjective)	vaulting (adjective)
revealing excessive self-confidence; reaching for the heights	revealing excessive self-confidence; reaching for the heights