只可意会，不可言传
zhǐ​kě​yì​huì​bù​kě​yán​chuán

can be understood but not described

只可意会，不可言传 只可意會，不可言傳 zhǐ​kě​yì​huì​bù​kě​yán​chuán
can be understood but not described
can only be felt or understood through intuition and experience, but cannot be expressed with words; mysterious and subtle; used to describe profound truths or feelings (from Zhuangzi)