In shoe sizing, "EEE" means "men's extra wide width." It is one of the widest available shoe sizes for men in the United States. Size "EE" is the "extra wide width" shoe size in women's shoes, and "wide width" in men's shoes.
The width size of a shoe is typically assigned a letter, with a higher letter indicating a wider shoe. The medium, or normal, width shoe is size D for men and B for women. Occasionally, a more general system is used, with size N for a narrow width, size M for a medium width and size W for a wide width. There is no standard measurement for each width size and sizes can vary between companies.