What is a "pleat"?

A pleat is a fold-in fabric that is made by doubling the fabric over and sewing it in place. It is commonly used in clothing, such as skirts and pants, as well as in home decor, such as curtains and tablecloths. Pleats can be formed in various ways, including by folding the fabric in one direction or alternating folds in opposite directions. They can also be formed using different stitching techniques, such as a box pleat or knife pleat. Pleats can add visual interest to a garment or item and can also serve a functional purpose, such as allowing for ease of movement.