device vs gimmick

device and gimmick both are nouns.

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

As nouns, device and gimmick are synonyms defined as:

Other synonyms of device include twist.

device (noun)	gimmick (noun)
any clever maneuver	any clever maneuver
an instrumentality invented for a particular purpose	something unspecified whose name is either forgotten or not known
an emblematic design (especially in heraldry)	a drawback or difficulty that is not readily evident
any ornamental pattern or design (as in embroidery)
something in an artistic work designed to achieve a particular effect