High-water pants are slacks with a length that sits above the ankle. They are also called "flood pants" or "flooders." The name comes from their being so high that the hem is protected from getting wet even in flood waters.
The term "high-water pants" first came into use in the 1850s. They are often seen on children who have grown so much that their pants are too short. They are not to be confused with crop pants or capris that are deliberately of a length above the ankles. High-water pants are generally considered a fashion faux pas and are associated with people who are not in style, according to About.com Men's Fashion.