这个只是别称用英文怎么说

这个别称用英语叫做 nickname，来源于英文"an ekename"，意思是"附加名"或"外号"。

例句：

His nickname is "Joker" because he always tells jokes. (他的别称是"小丑"，因为他总是讲笑话。)
I never knew her real name, everyone just called her "Red" because of her bright red hair. (我从来不知道她真名，大家都叫她"红"，因为她有一头鲜红的头发。)