damper vs piano damper

damper and piano damper both are nouns.

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

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

damper: a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations
piano damper: damper consisting of a small felted block that drops onto a piano string to stop its vibration

Other hyponyms of damper include damper block, dash-pot, cushion, shock, shock absorber.

damper (noun)	piano damper (noun)
a depressing restraint	damper consisting of a small felted block that drops onto a piano string to stop its vibration
a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations
a movable iron plate that regulates the draft in a stove or chimney or furnace