From the Folklore of the Netherlands, a person of Jebber. People from Jebber were known for their incomprenhesive and often insane speech.
To be a vanjebber is not only to talk shit but to converse in a low way. People from Jebber are considered to be particularly ignorant, uneducated and of low intellect, and are very often lacivious.
Their speech relects this inherent lack of intellect, education and morals.
that vanjebber has all the wit and charm of a diseased anchovy.