stonefly vs stone fly

stonefly and stone fly both are nouns.

Word	Noun	Adjective	Verb	Adverb
stonefly	Yes	No	No	No
stone fly	Yes	No	No	No

As nouns, stonefly and stone fly are synonyms defined as:

stonefly and stone fly: primitive winged insect with a flattened body; used as bait by fishermen; aquatic gilled larvae are carnivorous and live beneath stones

Other synonyms of stonefly include plecopteran.

stonefly (noun)	stone fly (noun)
primitive winged insect with a flattened body; used as bait by fishermen; aquatic gilled larvae are carnivorous and live beneath stones	primitive winged insect with a flattened body; used as bait by fishermen; aquatic gilled larvae are carnivorous and live beneath stones