"双胞胎哥哥"用英语可以说作"twin brother"。
"Twin"是指双胞胎，来源于中世纪拉丁语"gemellus"，意为"二倍的"或"双倍的"。
"Brother"是指兄弟，来源于古英语"brōþor"，意为"兄弟"。
例句：
My twin brother and I look very similar. (我和我的双胞胎哥哥长得很像。)
He is always competing with his twin brother. (他总是和他的双胞胎哥哥竞争。)
I can't tell my twin brother and his identical twin apart. (我分不清我的双胞胎哥哥和他的同卵双胞胎。)