bottle capper vs device

bottle capper and device both are nouns.

Word	Noun	Adjective	Verb	Adverb
bottle capper	Yes	No	No	No
device	Yes	No	No	No

As nouns, device is a hypernym of bottle capper; that is, device is a word with a broader meaning than bottle capper:

bottle capper (noun)	device (noun)
A manual or automatic device that is used to cap bottles.	any clever maneuver
	an instrumentality invented for a particular purpose
	an emblematic design (especially in heraldry)
	any ornamental pattern or design (as in embroidery)
	something in an artistic work designed to achieve a particular effect