greenbottle vs blow fly

greenbottle and blow fly both are nouns.

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

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

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

Other hypernyms of greenbottle include blowfly.

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