拜把子

拜把子

Literally means:

become sworn brothers or sisters

Actually means:

It was an old tradition for alliance. The phrase means that some friends, based on their emotion, personal loyalty or a common goal, go though a certain ceremony and acknowledge themselves as brothers with different surnames. And they are called 把兄弟 among themselves.

旧时的结盟习俗。指几个朋友基于感情、义气或共同目的，通过一定的仪式结为异姓兄弟（叫“把兄弟”）。