abbreviation of the word Yazoo, a popular milkshake brand but can also be used to describe a fan of Yazoo milkshakes, a person who drinks a bottle of Yazoo on a regular basis as though it is the elixir of life, their obsession with the drink may lead to anger if faced with withdrawal and financial hardship as they become dependant on a bottle of Yazoo to keep them going.
Yaz you need to stop this, you've already had a whole multipack and its not even 10am yet