斬雞頭燒黄紙 [斩鸡头烧－纸]

Jyutping zaam2 gai1 tau4 siu1 wong4 zi2
Pinyin zhǎn ji1tōu shāo huáng zhǐ

Definitions (CC-CANTO)
  1. to swear an oath and become sworn brothers (colloquial)