訣竅

诀窍
juéqiào
  1. secret
  2. trick
  3. knack
  4. key

CEDICT

Entry Composition

1 訣 jué
  1. to bid farewell
  2. tricks of the trade
  3. pithy mnemonic formula (e.g. Mao Zedong's 16-character mantra 十六字訣 on guerrilla warfare)
2 竅 qiào
  1. hole
  2. opening
  3. orifice (of the human body)
  4. (fig.) key (to the solution of a problem)