Larus ridibundus vs pewit gull

Larus ridibundus and pewit gull both are nouns.

Word	Noun	Adjective	Verb	Adverb
Larus ridibundus	Yes	No	No	No
pewit gull	Yes	No	No	No

As nouns, Larus ridibundus and pewit gull are synonyms defined as:

Other synonyms of Larus ridibundus include blackcap, laughing gull, pewit.

Larus ridibundus (noun)	pewit gull (noun)
small black-headed European gull	small black-headed European gull