Learn how to say Avouch correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word avouch:
[with object] archaic
affirm or assert:
the locket contains ringlets which he avouches to be relics of a Spanish girl
late 15th century: from Old French avochier, from Latin advocare ‘summon in defence’, from ad- ‘to’ + vocare ‘to call’