可以意會，不可言傳 [－－－会－－－－传]

Jyutping ho2 ji5 ji3 wui6 , bat1 ho2 jin4 cyun4
Pinyin kě yǐ yì huì , bù kě yán chuán

Definitions (CC-CEDICT)
  1. can be understood, but not described (idiom, from Zhuangzi 莊子|庄子[Zhuang1 zi3]); mysterious and subtle