blacksnake vs black racer

blacksnake and black racer both are nouns.

Word	Noun	Adjective	Verb	Adverb
blacksnake	Yes	No	No	No
black racer	Yes	No	No	No

As nouns, blacksnake and black racer are synonyms defined as:

blacksnake and black racer: blackish racer of the eastern United States that grows to six feet

Other synonyms of blacksnake include Coluber constrictor.

blacksnake (noun)	black racer (noun)
blackish racer of the eastern United States that grows to six feet	blackish racer of the eastern United States that grows to six feet
large harmless shiny black North American snake