Topdrest means to add a layer of nutrient-rich material to the surface of soil in order to promote plant growth. There are several synonyms for this word, including topdressing, topsoiling, mulching, and dressing. Topdressing is commonly used in lawn care to provide nutrients to grass and keep it healthy, while topsoiling refers to adding topsoil to improve the quality of soil. Mulching involves covering the soil with organic material such as leaves or straw to provide nutrients and conserve moisture. Dressing can also refer to adding fertilizer or other materials to soil. Overall, these synonyms all refer to the practice of improving soil quality for better plant growth.