avouchment vs asseveration

avouchment and asseveration both are nouns.

Word	Noun	Adjective	Verb	Adverb
avouchment	Yes	No	No	No
asseveration	Yes	No	No	No

As nouns, asseveration is a hypernym of avouchment; that is, asseveration is a word with a broader meaning than avouchment:

avouchment: a statement asserting the existence or the truth of something
asseveration: a declaration that is made emphatically (as if no supporting evidence were necessary)

Other hypernyms of avouchment include assertion, averment.

avouchment (noun)	asseveration (noun)
a statement asserting the existence or the truth of something	a declaration that is made emphatically (as if no supporting evidence were necessary)