验证 yànzhèng HSK7 to verify Origin Definitions Defs Strokes Stroke Words Sentences Sents 概念验证 gàiniànyànzhèng proof of concept 验证码 yànzhèngmǎ verification code verification code or CAPTCHA; a code used in computing to confirm that a user is human, often appearing as a combination of numbers and letters in a distorted image