White substance is a general term used to describe any material that is white in color and has a distinctive texture. Some common synonyms for white substance include chalk, clay, flour, powder, and snow. Chalk is a soft, white sedimentary rock that is often used for writing or drawing. Clay is a type of earth material that is often used for pottery or sculptures. Flour is a finely ground powder made from grains or other foods and is often used in baking. Powder is a substance that is finely ground and may include sugar, spices, or medications. Snow is a type of frozen precipitation that is white in color and forms during winter months.