gas fixture vs device

gas fixture and device both are nouns.

Word	Noun	Adjective	Verb	Adverb
gas fixture	Yes	No	No	No
device	Yes	No	No	No

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

gas fixture: a device to convey illuminating gas from the pipe to the gas burner
device: an instrumentality invented for a particular purpose

gas fixture (noun)	device (noun)
a device to convey illuminating gas from the pipe to the gas burner	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