taillight vs rear lamp

taillight and rear lamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
taillight	Yes	No	No	No
rear lamp	Yes	No	No	No

As nouns, taillight and rear lamp are synonyms defined as:

taillight and rear lamp: lamp (usually red) mounted at the rear of a motor vehicle

Other synonyms of taillight include rear light, tail lamp.

taillight (noun)	rear lamp (noun)
lamp (usually red) mounted at the rear of a motor vehicle	lamp (usually red) mounted at the rear of a motor vehicle