upright vs semi-upright

upright is a noun but semi-upright is not a noun.

Word	Noun	Adjective	Verb	Adverb
upright	Yes	Yes	No	No
semi-upright	No	Yes	No	No

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

upright (adjective)	semi-upright (adjective)
upright in position or posture	of animals that are partly erect
of moral excellence
in a vertical position; not sloping