斬雞頭燒黄紙 (zaam2 gai1 tau4 siu1 wong4 zi2) — to swear an oath and become sworn brothers (colloquial) in Cantonese
zaamˊ²斬gaiˉ¹雞tauˎ₄頭siuˉ¹燒wongˎ₄黄ziˊ²紙简 斩鸡头烧黄纸
Mandarin Pinyin: zhan3 ji1tou2 shao1 huang2 zhi3
Meaning of 斬雞頭燒黄紙
nounto swear an oath and become sworn brothers (colloquial)