We have contracted a famous lawyer who is ready to take the case to court if our demands are not met by the end of the year.

contracted 是动词 contract 的过去分词形式。contract 在这里的意思是"签订合同、聘请"，特指通过正式合同聘请专业人士提供服务。 contract 由前缀 con-（表示"共同"）和 tract（来自拉丁语 trahere，意为"拉、牵引"）组成，原意是"把双方拉到一起"，引申为"签订合同"。