stink fly vs goldeneye

stink fly and goldeneye both are nouns.

Word	Noun	Adjective	Verb	Adverb
stink fly	Yes	No	No	No
goldeneye	Yes	No	No	No

As nouns, goldeneye is a hyponym of stink fly; that is, goldeneye is a word with a more specific, narrower meaning than stink fly:

stink fly: pale green unpleasant-smelling lacewing fly having carnivorous larvae
goldeneye: a variety of green lacewing

Other hyponyms of stink fly include golden-eyed fly.

stink fly (noun)	goldeneye (noun)
pale green unpleasant-smelling lacewing fly having carnivorous larvae	large-headed swift-flying diving duck of Arctic regions
	a variety of green lacewing