A broad rectangular piece of fabric serving as a basic article of bedding. A broad, thin, usually rectangular mass or piece of material, such as paper, metal, glass, or plywood. A flat or very shallow, usually rectangular pan used for baking. A broad, flat, continuous surface or expanse: a sheet of ice. A moving expanse: a sheet of flames. A newspaper, especially a tabloid. Geology A broad, relatively thin deposit or layer of igneous or sedimentary rock. A large block of stamps printed by a single impression of a plate before the individual stamps have been separated. Mathematics A surface of revolution generated by revolving a hyperbola about one of its two symmetric axes. To cover with, wrap in, or provide with a sheet. To make into sheets. To flow or fall in a sheet: rain sheeting against the windshield. Being in the form of a sheet: sheet aluminum. A rope or chain attached to one or both of the lower corners of a sail, serving to move or extend it. The spaces at either end of an open boat in front of and behind the seats. To extend in a certain direction. Used of the sheets of a sail. to Informal Intoxicated; drunk.