cancel a contract 中止合同，撤销或取消合约或者合同

【例句】
The right to cancel a contract obtained by agreement differs from that by provisions of law.
合同解除权产生的情形因约定和法定解除权的不同而不同。

Lurking in the pile might be a killer memo from a customer, for example, who is threatening to cancel a contract unless his grievance is addressed forthwith.
藏在文件堆里的也许是一份杀手级备忘录，例如，来自客户的威胁：除非他的投诉能立刻得到解决，否则就会取消合同。