merlin vs Falco columbarius

merlin and Falco columbarius both are nouns.

Word	Noun	Adjective	Verb	Adverb
merlin	Yes	No	No	No
Falco columbarius	Yes	No	No	No

As nouns, merlin and Falco columbarius are synonyms defined as:

merlin and Falco columbarius: small falcon of Europe and America having dark plumage with black-barred tail; used in falconry

Other synonyms of merlin include pigeon hawk.

merlin (noun)	Falco columbarius (noun)
small falcon of Europe and America having dark plumage with black-barred tail; used in falconry	small falcon of Europe and America having dark plumage with black-barred tail; used in falconry