心照不宣

xīnzhàobùxuān
to have a tacit understanding

CEDICT

to understand something but not voice it; to have a tacit understanding

Wiktionary

彼此心裡明白，不必言语说明。

重編國語辭典

彼此心裡明白，不必言语说明

維基詞典

Entry Composition

1 心照 xīnzhào to have a tacit understanding
2 不 bù
  1. no; not so
  2. (bound form) not; un-
3 宣 xuān
  1. to declare (publicly)
  2. to announce

Related entries

心照 xīnzhào to have a tacit understanding