sound bow vs tangency

sound bow and tangency both are nouns.

Word	Noun	Adjective	Verb	Adverb
sound bow	Yes	No	No	No
tangency	Yes	No	No	No

As nouns, tangency is a hypernym of sound bow; that is, tangency is a word with a broader meaning than sound bow:

sound bow: contact (the part of a bell) against which the clapper strikes
tangency: (electronics) a junction where things (as two electrical conductors) touch or are in physical contact

Other hypernyms of sound bow include contact.

sound bow (noun)	tangency (noun)
contact (the part of a bell) against which the clapper strikes	(electronics) a junction where things (as two electrical conductors) touch or are in physical contact
	the state of being tangent; having contact at a single point or along a line without crossing