federation vs confederacy

federation and confederacy both are nouns.

Word	Noun	Adjective	Verb	Adverb
federation	Yes	No	No	No
confederacy	Yes	No	No	No

As nouns, federation and confederacy are synonyms defined as:

Other synonyms of federation include confederation.

federation (noun)	confederacy (noun)
the act of constituting a political unity out of a number of separate states or colonies or provinces so that each member retains the management of its internal affairs	a secret agreement between two or more people to perform an unlawful act
a union of political organizations	a union of political organizations
an organization formed by merging several groups or parties	a group of conspirators banded together to achieve some harmful or illegal purpose