What does the Adidas symbol mean?

It's not really a Word. It's the abbreviated version of the name of the German man who founded the company: Adolf "Adi" Dassler. (The closest we might come to "Adidas" would be two non-related Words in Hindi, the main language of India-- Adi, which means "the first" and "das" which is a title sometimes given to a male devotee of Hinduism.)