後うしろ指ゆびを指さす

expression, godan verb (-su)

talk behind someone's back; backbite

Idiomatic expression meaning to speak ill of someone in their absence. Rare in modern conversation; more common in literary or dramatic contexts.

• 彼かれはいつも同どう僚りょうの後うしろ指ゆびを指さすようなことを言いう。

  He always says things that are like talking behind his colleagues' backs.

• 後うしろ指ゆびを指さされるような行こう為いは慎つつしむべきだ。

  You should avoid behavior that would make people talk behind your back.