golden-crested kinglet vs goldcrest

golden-crested kinglet and goldcrest both are nouns.

Word	Noun	Adjective	Verb	Adverb
golden-crested kinglet	Yes	No	No	No
goldcrest	Yes	No	No	No

As nouns, golden-crested kinglet and goldcrest are synonyms defined as:

golden-crested kinglet and goldcrest: European kinglet with a black-bordered yellow crown patch

Other synonyms of golden-crested kinglet include Regulus regulus.

golden-crested kinglet (noun)	goldcrest (noun)
European kinglet with a black-bordered yellow crown patch	European kinglet with a black-bordered yellow crown patch