idiot light vs warning light

idiot light and warning light both are nouns.

Word	Noun	Adjective	Verb	Adverb
idiot light	Yes	No	No	No
warning light	Yes	No	No	No

As nouns, warning light is a hypernym of idiot light; that is, warning light is a word with a broader meaning than idiot light:

idiot light: a colored warning light on an instrument panel (as for low oil pressure)
warning light: a cautionary sign of danger

Other hypernyms of idiot light include red light.

idiot light (noun)	warning light (noun)
a colored warning light on an instrument panel (as for low oil pressure)	a cautionary sign of danger