The German sportswear company makes Adidas and Reebok brands of shoes, clothing and sportswear. Adidas isn’t a word or a proper name: It’s a hybrid taken from an actual person’s first and last names. The founder of Adidas was a man called Adolf Dassler and his nickname was Adi. Adidas is simply a combination of Adi combined with Das for Dassler. The result? AdiDas, or Adidas.
Adidas is pronounced “ah-dee-dahs,”* with the emphasis on the first syllable, not “ah-DEE-dus.”
*Source: Forvo, the largest pronunciation dictionary in the world, based on pronunciations by native speakers.