blighter vs gadfly

blighter and gadfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
blighter	Yes	No	No	No
gadfly	Yes	No	No	No

As nouns, blighter and gadfly are synonyms defined as:

Other synonyms of blighter include cuss, pest, pesterer.

blighter (noun)	gadfly (noun)
a persistently annoying person	any of various large flies that annoy livestock
a boy or man	a persistently annoying person