D'blok

From Memory Alpha, the free Star Trek reference

D'blok is a word in Klingonese that can be used as an insult.

In 2372 Chancellor Gowron called Worf a mute d'blok, when Worf didn't answer Gowron's offer to come with him to Cardassia Prime, immediately. (DS9: "The Way of the Warrior")

It is unclear what exactly the Klingon word d'blok means.