baby's dummy vs device

baby's dummy and device both are nouns.

Word	Noun	Adjective	Verb	Adverb
baby's dummy	Yes	No	No	No
device	Yes	No	No	No

As nouns, device is a hypernym of baby's dummy; that is, device is a word with a broader meaning than baby's dummy:

baby's dummy (noun)	device (noun)
device used for an infant to suck or bite on	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