fellow vs blighter

fellow and blighter both are nouns.

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

As nouns, fellow and blighter are synonyms defined as:

Other synonyms of fellow include bloke, chap, cuss, fella, feller, gent, lad.

fellow (noun)	blighter (noun)
a boy or man	a persistently annoying person
a man who is the lover of a man or woman	a boy or man
a friend who is frequently in the company of another
a person who is member of one's class or profession
an informal form of address for a man
a member of a learned society
one of a pair