taillight vs tail lamp

taillight and tail lamp both are nouns.

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

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

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

Other synonyms of taillight include rear lamp, rear light.

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