alder fly vs alderfly

alder fly and alderfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
alder fly	Yes	No	No	No
alderfly	Yes	No	No	No

As nouns, alder fly and alderfly are synonyms defined as:

alder fly and alderfly: dark-colored insect having predaceous aquatic larvae

Other synonyms of alder fly include Sialis lutaria.

alder fly (noun)	alderfly (noun)
dark-colored insect having predaceous aquatic larvae	dark-colored insect having predaceous aquatic larvae