To deny, disclaim, or refuse to vouch for; to disown or repudiate something.
From dis- (prefix meaning 'reverse') + avouch (from Old French avoucher, 'to call upon' or 'to vouch for'). Avouch itself is now archaic, making disavouch even rarer.
This word is mainly found in early modern English texts like those from the 1500s-1600s. It's interesting because we've completely replaced it with simpler words like 'deny' or 'disclaim'—showing how language naturally prunes its vocabulary.
Complete word intelligence in one call. Free tier — 50 lookups/day.