dabchick vs grebe

dabchick and grebe both are nouns.

Word	Noun	Adjective	Verb	Adverb
dabchick	Yes	No	No	No
grebe	Yes	No	No	No

As nouns, grebe is a hypernym of dabchick; that is, grebe is a word with a broader meaning than dabchick:

dabchick: small European grebe
grebe: small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet

dabchick (noun)	grebe (noun)
small European grebe	small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet