auk vs razor-billed auk

auk and razor-billed auk both are nouns.

Word	Noun	Adjective	Verb	Adverb
auk	Yes	No	No	No
razor-billed auk	Yes	No	No	No

As nouns, razor-billed auk is a hyponym of auk; that is, razor-billed auk is a word with a more specific, narrower meaning than auk:

auk: black-and-white short-necked web-footed diving bird of northern seas
razor-billed auk: black-and-white northern Atlantic auk having a compressed sharp-edged bill

auk (noun)	razor-billed auk (noun)
black-and-white short-necked web-footed diving bird of northern seas	black-and-white northern Atlantic auk having a compressed sharp-edged bill