forte-piano vs upright

forte-piano and upright both are nouns.

Word	Noun	Adjective	Verb	Adverb
forte-piano	Yes	No	No	No
upright	Yes	Yes	No	No

As nouns, upright is a hyponym of forte-piano; that is, upright is a word with a more specific, narrower meaning than forte-piano:

forte-piano: a keyboard instrument that is played by depressing keys that cause hammers to strike tuned strings and produce sounds
upright: a piano with a vertical sounding board

Other hyponyms of forte-piano include grand, grand piano, mechanical piano, Pianola, player piano, upright piano.

forte-piano (noun)	upright (noun)
a keyboard instrument that is played by depressing keys that cause hammers to strike tuned strings and produce sounds	a piano with a vertical sounding board
	a vertical structural member as a post or stake

forte-piano (adjective)	upright (adjective)
	upright in position or posture
	of moral excellence
	in a vertical position; not sloping