pewit gull vs laughing gull

pewit gull and laughing gull both are nouns.

Word	Noun	Adjective	Verb	Adverb
pewit gull	Yes	No	No	No
laughing gull	Yes	No	No	No

As nouns, pewit gull and laughing gull are synonyms defined as:

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

pewit gull (noun)	laughing gull (noun)
small black-headed European gull	small black-headed European gull