acknowledge vs avouch

acknowledge and avouch both are verbs.

Word	Noun	Adjective	Verb	Adverb
acknowledge	No	No	Yes	No
avouch	No	No	Yes	No

As verbs, avouch is a hyponym of acknowledge; that is, avouch is a word with a more specific, narrower meaning than acknowledge:

acknowledge: declare to be true or admit the existence or reality or truth of
avouch: admit openly and bluntly; make no bones about

acknowledge (verb)	avouch (verb)
accept as legally binding and valid	admit openly and bluntly; make no bones about
accept (someone) to be what is claimed or accept his power and authority
declare to be true or admit the existence or reality or truth of
express obligation, thanks, or gratitude for
report the receipt of
express recognition of the presence or existence of, or acquaintance with