n. A large square or rectangular piece of linen or cotton spread over a bed, under the covers, next to the sleeper: as, to sleep between sheets.n. In general, a broad, usually flat, and relatively thin piece of anything, either very flexible, as linen, paper, etc., or less flexible, or rigid, as lead, tin, iron, glass, etc. (a plate).n. One of the separate pieces, of definite size, in which paper is made; the twenty-fourth part of a quire. In the printing-trade the sheet is more clearly defined by naming its size: as, a sheet of cap or a sheet of royal (see sizes of paper, under paper); in bookbinding the sheet is further defined by specifying its fold: as, a sheet of quarto or a sheet of duodecimo.n. A newspaper: so called as being usually printed on a large piece of paper and folded.n. plural Leaves and pages, as of a book or a pamphlet.n. In mathematics, a separate portion of a surface, analogous to the branch of a curve; especially, one of the planes of a Riemann's surface.n. [Sheet is often used in composition to denote that the substance to the name of which it is prefixed is in the form of sheets or thin plates: as, sheet-iron, sheet-glass, sheet-tin.]n. A broad expanse or surface: as, a sheet of water, of ice, or of flame.n. A sail.n. Nautical, a rope or chain fastened to one or both of the lower corners of a sail to extend it and hold it extended, or to change its direction.n. In anatomy and zoology, a layer; a lamina or lamella, as of any membranous tissue.n. In mining, galena in thin and continuous masses. The ore itself is frequently called sheet-mineral.To furnish with sheets: as, a sheeted c ouch.To fold in a sheet; shroud; cover with or as with a sheet.To form into sheets; arrange in or as in sheets.An old variant of shoot, used in sheet-anchor, and common in dialectal speech.n. plural A commercial name for crude rubber in thin pieces formed by coagulating the latex on a large leaf. See rubber, 3.n. In geology: A mass of eruptive rock of great length and breadth as compared with its thickness. Two principal varieties are recognized: surface flows, which are poured out on the surface of the earth, and intruded or intrusive sheets, which are forced between relatively horizontal stratan. A deposit of any material, sedimentary or other, which has great areal extent and small thickness.