pair vs fellow

pair and fellow both are nouns.

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

pair (noun)	fellow (noun)
two people considered as a unit	a boy or man
a set of two similar things considered as a unit	a man who is the lover of a man or woman
a poker hand with 2 cards of the same value	a friend who is frequently in the company of another
two items of the same kind	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

pair (verb)	fellow (verb)
engage in sexual intercourse
bring two objects, ideas, or people together
arrange in pairs
occur in pairs
form a pair or pairs