cognomen
/kɒgˈnəʊmen/noun
1- an extra personal name given to an ancient Roman citizen, functioning rather like a nickname and typically passed down from father to son（古罗马人的）第三个名字（相当于外号, 尤指父传子者）。
1.1
- a name; a nickname.名字; 外号, 绰号。
词源
Latin, from co- 'together with' + gnomen, nomen 'name'.