Definition of "pleat"

(sewing) A fold in the fabric of a garment, usually a skirt, as a part of the design of the garment, with the purpose of adding controlled fullness and freedom of movement, or taking up excess fabric. There are many types of pleats, differing in their construction and appearance.  examples

(botany) A fold in an organ, usually a longitudinal fold in a long leaf such as that of palmetto, lending it stiffness.  examples

A plait.  examples

(transitive) To form one or more pleats in a piece of fabric or a garment.  examples

To plait.  examples