Flour is a powder which is made from grinding up cereal grains, other seeds, orroots. It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history.
The word "flour" is originally a variant of the word "flower". Both derive from the Old French fleur or flour, which had the literal meaning "blossom," and a figurative meaning "the finest." The phrase "fleur de farine" meant "the finest part of the meal," since flour resulted from the elimination of coarse and unwanted matter from the grain during milling.
Flour dust suspended in air is explosive -- as is any mixture of a finely powdered flammable substance with air. Some devastating and fatal explosions have occurred at flour mills, including an explosion in 1878 at the Washburn "A" Mill in Minneapolis, the largest flour mill in the United States at the time.
Bread, pasta, crackers, many cakes, and many other foods are made using flour. Wheat flour is also used to make a roux as a base forgravy and sauces. White wheat flour is the traditional base for wallpaper paste. It is also the base for papier-mâché.