brotherly vs fraternal

brotherly and fraternal both are adjectives.

Word	Noun	Adjective	Verb	Adverb
brotherly	No	Yes	No	Yes
fraternal	No	Yes	No	No

As adjectives, brotherly and fraternal are synonyms defined as:

brotherly and fraternal: like or characteristic of or befitting a brother

Other synonyms of brotherly include brotherlike.

brotherly (adjective)	fraternal (adjective)
like or characteristic of or befitting a brother	(of twins) derived from two separate fertilized ova
	like or characteristic of or befitting a brother
	of or relating to a fraternity or society of usually men

brotherly (adverb)	fraternal (adverb)
(archaic as adverb) in a manner characteristic of a brother