1. to declare or assert positively; to affirm or guarantee
Usage: formal; archaic

Examples

• He avouches his innocence in the matter.
• The witness avouches that she saw the defendant at the scene.
• She avouches the truth of her testimony.
• The document avouches the authenticity of the signature.
• He avouches his commitment to the cause.
• The expert avouches the accuracy of the results.