It is gayboy spelt backwards. Not meant to be used as an anti-homosexual term, but as a general insult. Used in place of words such as: idiot, dumbass, retard...etc.
Ashe: Hey do you guys listen to Emo?
Dave: You yobyag, Emo sucks.
Jeremy: Gah.
A rude, noisy, and aggressive youth under the influence of alcohol giving the youth the properties of a late predator in the fashion like a dinosaur, and earning the first half from the term Yob as like a rude, noisy, and aggressive youth. This can cause the vicinity of the 'Yobagaurous' to become hard to accommodate as the youth like creature causes raucous as like a dinosaur would in the current world. Many find this distressing as the Yobagaurous will interact negatively with any being around it.
'When I went to Eastern Londonyesterday I noticed that some quite possibly intoxicated teen was causing raucous, he must have been a Yobagaurous to the public!'
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.