piano vs pianist

piano and pianist both are nouns.

Word	Noun	Adjective	Verb	Adverb
piano	Yes	Yes	No	Yes
pianist	Yes	No	No	No

piano (noun)	pianist (noun)
a keyboard instrument that is played by depressing keys that cause hammers to strike tuned strings and produce sounds	a person who plays the piano
(music) low loudness

piano (adjective)	pianist (adjective)
(used chiefly as a direction or description in music) soft; in a quiet, subdued tone

piano (adverb)	pianist (adverb)
used as a direction in music; to be played relatively softly