great auk vs auk

great auk and auk both are nouns.

Word	Noun	Adjective	Verb	Adverb
great auk	Yes	No	No	No
auk	Yes	No	No	No

As nouns, auk is a hypernym of great auk; that is, auk is a word with a broader meaning than great auk:

great auk: large flightless auk of rocky islands off northern Atlantic coasts; extinct
auk: black-and-white short-necked web-footed diving bird of northern seas

great auk (noun)	auk (noun)
large flightless auk of rocky islands off northern Atlantic coasts; extinct	black-and-white short-necked web-footed diving bird of northern seas