When something shudders, it shakes violently and quickly: I heard a massive explosion and the ground shuddered beneath me. There was a screech of brakes and the bus shuddered to a halt (= shook violently and stopped).

What does shuddered mean?

verb. (intr) to shake or tremble suddenly and violently, as from horror, fear, aversion, etc.

What is a sudder?

(esp of a government office) supreme; highest; chief.