laughing gull vs pewit gull

laughing gull and pewit gull both are nouns.

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

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

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

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