American creeper vs brown creeper

American creeper and brown creeper both are nouns.

Word	Noun	Adjective	Verb	Adverb
American creeper	Yes	No	No	No
brown creeper	Yes	No	No	No

As nouns, American creeper and brown creeper are synonyms defined as:

American creeper and brown creeper: a common creeper in North America with a down-curved bill

Other synonyms of American creeper include Certhia americana.

American creeper (noun)	brown creeper (noun)
a common creeper in North America with a down-curved bill	a common creeper in North America with a down-curved bill