piano vs soft pedal

piano and soft pedal both are nouns.

Word	Noun	Adjective	Verb	Adverb
piano	Yes	Yes	No	Yes
soft pedal	Yes	No	No	No

piano (noun)	soft pedal (noun)
a keyboard instrument that is played by depressing keys that cause hammers to strike tuned strings and produce sounds	a pedal on a piano that moves the action closer to the strings and so soften the sound
(music) low loudness

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

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