n.

1. 兄弟关系；手足之情[U]
   Soldiers who are fighting together often have a strong feeling of brotherhood.

   一起作战的士兵相互间常怀有深厚的兄弟情谊。

2. 同志关系[U]
3. 兄弟会；同志会；同业公会；修士会[C]
4. （总称）同行，同业；会友[the S][G]
   the medical brotherhood

   医务界

5. 四海之内皆兄弟的信念

n.

1. the relationship between brothers.
   ▸a feeling of kinship and closeness.
2. an association or community of people with a common interest, religion, or trade.
   ▸N. Amer. a trade union.