tympan vs percussion instrument

tympan and percussion instrument both are nouns.

Word	Noun	Adjective	Verb	Adverb
tympan	Yes	No	No	No
percussion instrument	Yes	No	No	No

As nouns, percussion instrument is a hypernym of tympan; that is, percussion instrument is a word with a broader meaning than tympan:

tympan: a musical percussion instrument; usually consists of a hollow cylinder with a membrane stretched across each end
percussion instrument: a musical instrument in which the sound is produced by one object striking another

Other hypernyms of tympan include percussive instrument.

tympan (noun)	percussion instrument (noun)
a musical percussion instrument; usually consists of a hollow cylinder with a membrane stretched across each end	a musical instrument in which the sound is produced by one object striking another