司马昭之心路人皆知

司馬昭之心路人皆知
Sīmǎ Zhāozhīxīnlùrénjiēzhī
  1. lit. Sima Zhao's intentions are obvious to everyone (idiom)
  2. fig. an open secret

CEDICT

Entry Composition

1 司马昭之心 Sīmǎ Zhāozhīxīn evil ambitions that are transparent to everyone
2 路人皆知 lùrénjiēzhī
  1. understood by everyone (idiom); well known
  2. a household name