動詞 avouch:

1. admit openly and bluntly; make no bones about
   同義詞：avow

a.vouch

v.tr.（及物動詞）
a.vouched,a.vouch.ing,a.vouch.es
To declare the provable truth or validity of; affirm:
斷言：聲稱是可以證實的事實或其有效性；肯定：
例句：
She avouched that she herself was innocent.
她證實了她自己是無辜的

To vouch for.
為…證實
To accept responsibility for (an action, for example); acknowledge.
承擔：為（如某一行為）承擔責任；確認
To avow; confess.
承認；坦白

來源：
Middle English avouchen [to cite as a warrant]
中古英語 avouchen [作為擔保引用]
from Old French avochier
源自 古法語 avochier
from Latin advoc3re [to summon] * see advocate
源自 拉丁語 advoc3re [召喚] *參見 advocate