牛鼻子 [－－－]

Jyutping ngau4 bei6 zi2
Pinyin niú bí zi

Definitions (CC-CEDICT)
  1. key point
  2. crux
  3. (old) Daoist (facetious)
Definitions (Wiktionary)
  1. noun, figuratively
    crux; key element; crucial point
  2. noun, dated, informal
    Taoist priest
  3. noun
    Used other than figuratively or idiomatically: see 牛 (niú), 鼻子: ox muzzle