automobile driver vs racer

automobile driver and racer both are nouns.

Word	Noun	Adjective	Verb	Adverb
automobile driver	Yes	No	No	No
racer	Yes	No	No	No

As nouns, automobile driver and racer are synonyms defined as:

automobile driver and racer: someone who drives racing cars at high speeds

Other synonyms of automobile driver include race driver.

automobile driver (noun)	racer (noun)
someone who drives racing cars at high speeds	an animal that races
	slender fast-moving North American snakes
	a fast car that competes in races
	someone who drives racing cars at high speeds