The company received a cease-and-desist letter from their competitor.

cease 是动词，意思是"停止、终止"。 desist 也是动词，意思是"停止、不再做某事"，通常指停止某种行为或活动。 cease-and-desist 是一个法律术语，指要求对方立即停止某种行为的正式通知，通常用于知识产权侵权等法律纠纷中。