Paddle:

A widespread BDSM tool designed for spanking, specifically buttocks. Generally the Paddle is a wooden or leather implement with a long, flat face and narrow handle. Due to its large surface, inflexibility and flatness, paddle cannot cause stripes like a cane or a whip, but it may cause bruises.

A spanking paddle is an implement used to strike a person on the buttocks. The act of striking a person with a paddle is known as "paddling". A paddling may be for punishment  or for erotic purposes.

A paddle has two parts: a handle and a blade. Most paddles are designed to be held with one hand. Paddles come in a wide variety of shapes, sizes and styles and can be made from a variety of materials including wood and leather.

In the great majority of cases, the paddle is aimed at the recipient's buttocks; rarely, the back of the thighs might also be targeted.