The antithesis of what a good boy should be - rude, obnoxious, violent and stupid. Formed by spelling 'boy' bacwards, it was coined in England in the 18th century as it was very popular amongst upperclasses to speak backwards at the time.

A thugish young male.

Yobs:

Primarily British slang

Delinquent teenagers with their hoods up (as defined by the Tory party).

hooligan, ruffian

"Yobbo or yob is a slang term for an uncouth or thuggish working-class person. The word derives from a back slang reading of the word "boy" (boy or boyo reversed becomes yob or – slightly modified – yobbo)."

Definition borrowed from Wikipedia.

Mentioned in British Civilization: An Introduction by John Oakland (p.13).

Means backwards, twisted ass boy who thinks he's better than everyone. He puts others down, he thinks he is very strong and tries to fight your brother, says things like "stop hoeing around", "You're the biggest hoe of them all" "woop dee do", likes the song "All About That Bass"

A yob is a job that is tedious and/or pays a very low wage. Refers to the working conditions (and the way Mexicans would pronounce j-o-b in Spanish) of Mexican Americans.