Old World robin vs robin

Old World robin and robin both are nouns.

Word	Noun	Adjective	Verb	Adverb
Old World robin	Yes	No	No	No
robin	Yes	No	No	No

As nouns, Old World robin and robin are synonyms defined as:

Old World robin and robin: small Old World songbird with a reddish breast

Other synonyms of Old World robin include Erithacus rubecola, redbreast, robin redbreast.

Old World robin (noun)	robin (noun)
small Old World songbird with a reddish breast	large American thrush having a rust-red breast and abdomen
	small Old World songbird with a reddish breast