greenbottle fly vs blowfly

greenbottle fly and blowfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
greenbottle fly	Yes	No	No	No
blowfly	Yes	No	No	No

As nouns, blowfly is a hypernym of greenbottle fly; that is, blowfly is a word with a broader meaning than greenbottle fly:

greenbottle fly: blowfly with brilliant coppery green body
blowfly: large usually hairy metallic blue or green fly; lays eggs in carrion or dung or wounds

Other hypernyms of greenbottle fly include blow fly.

greenbottle fly (noun)	blowfly (noun)
blowfly with brilliant coppery green body	large usually hairy metallic blue or green fly; lays eggs in carrion or dung or wounds