() [] to state that you believe that sth is true or genuine, for example in a court 作证；证明◆to attest a will 为遗嘱作见证◆The signature was attested by two witnesses. 这签名有两名见证人。
() [] attest (to) sthto show, prove or give evidence that sth is true 证实◆They have a large client list of users who will attest to the effectiveness of their products. 他们有一个很长的客户名单，可以证实产品的有效性。