younger brother
英 ['jɡ(r) br(r)] 美 ['jɡr brr]
弟弟;小弟;幼弟
1、She had a twin brother and a younger brother.
她有一个双胞胎哥哥和一个弟弟。
2、Oh, so you're Peter's younger brother
哦,那么你是彼得的弟弟。