表弟的英语是"younger male cousin". 这个词来源于英文表达家庭关系的方式。在英文中，"cousin"是表示堂兄弟或堂姐妹的通用词。"Younger"表示比自己年纪小，"male"表示性别是男性。

例句：

My younger male cousin is coming to visit next week.

我的表弟下周要来看我。

I always enjoyed spending time with my younger male cousin when we were kids.

我们小时候，我总是喜欢和我的表弟在一起。

My parents are very proud of my younger male cousin who just graduated from college.

我父母非常为我的表弟毕业感到骄傲。