[no obj.]give evidence as a witness in a law court 作证 he testified against his own commander. 他做了不利于自己指挥官的证明。 [with clause]he testified that he had supplied Barry with crack. 他作证说他为巴里提供了可卡因。 ■serve as evidence or proof of something's existing or being the case 证明 the bleak lines testify to inner torment. 沟壑纵横的脸表明了内心所受的折磨。
派生 testifier noun 语源
late Middle English: from Latin testificari, from testis 'a witness'