blackcap vs Larus ridibundus

blackcap and Larus ridibundus both are nouns.

Word	Noun	Adjective	Verb	Adverb
blackcap	Yes	No	No	No
Larus ridibundus	Yes	No	No	No

As nouns, blackcap and Larus ridibundus are synonyms defined as:

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

blackcap (noun)	Larus ridibundus (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