blackcap vs laughing gull

blackcap and laughing gull both are nouns.

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

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

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

blackcap (noun)	laughing gull (noun)
small brownish-grey warbler with a black crown	small black-headed European gull
chickadee having a dark crown
small black-headed European gull
raspberry native to eastern North America having black thimble-shaped fruit