upright vs erect

upright is a noun but erect is not a noun.

Word	Noun	Adjective	Verb	Adverb
upright	Yes	Yes	No	No
erect	No	Yes	Yes	No

As adjectives, upright and erect are synonyms defined as:

Other synonyms of upright include vertical.

upright (noun)	erect (noun)
a piano with a vertical sounding board
a vertical structural member as a post or stake

upright (adjective)	erect (adjective)
upright in position or posture	upright in position or posture
of moral excellence	of sexual organs; stiff and rigid
in a vertical position; not sloping

upright (verb)	erect (verb)
	construct, build, or erect
	cause to rise up