stoplight vs brake light

stoplight and brake light both are nouns.

Word	Noun	Adjective	Verb	Adverb
stoplight	Yes	No	No	No
brake light	Yes	No	No	No

As nouns, stoplight and brake light are synonyms defined as:

stoplight and brake light: a red light on the rear of a motor vehicle that signals when the brakes are applied to slow or stop

stoplight (noun)	brake light (noun)
a visual signal to control the flow of traffic at intersections	a red light on the rear of a motor vehicle that signals when the brakes are applied to slow or stop
a red light on the rear of a motor vehicle that signals when the brakes are applied to slow or stop