genocide vs racial extermination

genocide and racial extermination both are nouns.

Word	Noun	Adjective	Verb	Adverb
genocide	Yes	No	No	No
racial extermination	Yes	No	No	No

As nouns, genocide and racial extermination are synonyms defined as:

genocide and racial extermination: systematic killing of a racial or cultural group

Other synonyms of genocide include race murder.

genocide (noun)	racial extermination (noun)
systematic killing of a racial or cultural group	systematic killing of a racial or cultural group