appanage vs fringe benefit

appanage and fringe benefit both are nouns.

Word	Noun	Adjective	Verb	Adverb
appanage	Yes	No	No	No
fringe benefit	Yes	No	No	No

As nouns, fringe benefit is a hypernym of appanage; that is, fringe benefit is a word with a broader meaning than appanage:

appanage: any customary and rightful perquisite appropriate to your station in life
fringe benefit: an incidental benefit awarded for certain types of employment (especially if it is regarded as a right)

Other hypernyms of appanage include perk, perquisite.

appanage (noun)	fringe benefit (noun)
a grant (by a sovereign or a legislative body) of resources to maintain a dependent member of a ruling family	an incidental benefit awarded for certain types of employment (especially if it is regarded as a right)
any customary and rightful perquisite appropriate to your station in life