A cognomen is something like an extra name given to a Roman citizen; it was something personal which functioned a bit like a nickname, but was typically passed from father to son.

姓氏就像是给罗马公外名字；这是个人名字，有点像昵，但通常是父亲传给儿子。

In 160 CE, Julia was born at Emesa, Syria and her cognomen, Domna, means " black" , which has to do with the sun god El-Gabal (Elagabalus) , whose cult stone was black.

公元 160 年，朱莉娅出生在叙利亚埃梅萨，她姓 Domna 意思是“黑色”，这与太阳神埃喇伽巴有关，他崇拜石是黑色。