renew

verb [vt. 及物动词]重新开始，中止后继续；恢复，重新建立（关系）；使（受到损毁或丢失后）重获新生；更换，更新；重申，重复强调；延长（执照、合同等）的有效期，使续签

When you renew something such as a licence or a contract, you extend the period of time for which it is valid. ^{延长 (执照、合同的) 有效期}