1. 同奶兄弟：stepsister 继姐妹 | foster brother 同奶兄弟 | uterine brother 异父兄弟
2. 奶兄弟：craft brother 同行 | foster brother 奶兄弟 | full brother 亲兄弟
3. 同奶兄弟; 义兄弟：foster 养育; 培养; 抚育 (动) | foster brother 同奶兄弟; 义兄弟 | foster child 养子; 养女
noun
1. your foster brother is a male who is not a son of your parents but who is raised by your parents
Synonym: foster-brother