pacifier vs device

pacifier and device both are nouns.

Word	Noun	Adjective	Verb	Adverb
pacifier	Yes	No	No	No
device	Yes	No	No	No

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

pacifier (noun)	device (noun)
device used for an infant to suck or bite on	any clever maneuver
anything that serves to pacify	an instrumentality invented for a particular purpose
someone who tries to bring peace	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