Planer/ˈpleɪnər/ Definition 1 of 3Pro Tip 1/3Tool Usage The word 'planer' refers to a tool often found in woodworking shops. She keeps her planer on a special shelf. Pro Tip 2/3Physical Action Using a planer involves moving it across the wood surface. Carefully, he moved the planer along the grain. Pro Tip 3/3Surface Finish 'Planer' implies creating a smooth, flat finish on wood. A planer helps achieve a perfectly flat surface.