What does the latin root mob mean?

There isn't a Latin root "mob". The word "mob" itself comes from the Latin word "mobile", which means "movable" or "changeable". It evolved into the English word "mob" through a couple of steps:

* "mobile" (Latin) - meaning "movable"

* "mobile vulgus" (Latin) - meaning "movable crowd"

* "mob" (English) - meaning a large, often disorderly crowd.

So, while "mob" itself isn't a Latin root, it's directly derived from the Latin word "mobile", reflecting the idea of a crowd being easily moved or swayed.