blow fly vs blowfly

blow fly and blowfly both are nouns.

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

As nouns, blow fly and blowfly are synonyms defined as:

blow fly and blowfly: large usually hairy metallic blue or green fly; lays eggs in carrion or dung or wounds

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