dayfly vs mayfly

dayfly and mayfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
dayfly	Yes	No	No	No
mayfly	Yes	No	No	No

As nouns, dayfly and mayfly are synonyms defined as:

dayfly and mayfly: slender insect with delicate membranous wings having an aquatic larval stage and terrestrial adult stage usually lasting less than two days

Other synonyms of dayfly include shadfly.

dayfly (noun)	mayfly (noun)
slender insect with delicate membranous wings having an aquatic larval stage and terrestrial adult stage usually lasting less than two days	slender insect with delicate membranous wings having an aquatic larval stage and terrestrial adult stage usually lasting less than two days