壁かべ訴そ訟しょう

noun

grumbling to oneself; muttering to oneself

Refers to complaining or talking to oneself, often when alone or when others are not listening. The literal meaning is 'wall lawsuit', evoking the image of arguing with a wall.

• 彼かれはいつも壁かべ訴そ訟しょうをしている。

  He is always grumbling to himself.

• 誰だれも聞きいていないのに、壁かべ訴そ訟しょうを繰くり返かえしていた。

  Even though no one was listening, he kept muttering to himself.