毫髮不爽 [－发－－]

Jyutping hou4 faat3 bat1 song2
Pinyin háo fà bù shuǎng

Definitions (CC-CEDICT)
  1. not to deviate one hair's breadth (idiom)
  2. to be extremely accurate
Definitions (Kaifangcidian)
  1. （沒有對應漢語詞彙）