mouthpiece vs fisticuffs

mouthpiece and fisticuffs both are nouns.

Word	Noun	Adjective	Verb	Adverb
mouthpiece	Yes	No	No	No
fisticuffs	Yes	No	No	No

mouthpiece (noun)	fisticuffs (noun)
the aperture of a wind instrument into which the player blows directly	fighting with the fists
the tube of a pipe or cigarette holder that a smoker holds in the mouth	a fight with bare fists
an acoustic device; the part of a telephone into which a person speaks
(especially boxing) equipment that protects an athlete's mouth
a part that goes over or into the mouth of a person
a spokesperson (as a lawyer)