Other forms: sheaves; sheafs
Those old love letters tied up with a ribbon at the back of your closet? Last week's newspapers bundled up for recycling? Each is a sheaf — a tied up bundle of something ready for storage or carrying.
Although sheaf almost always refers to bundles of paper, there's one striking exception to this, as any fan of Robin Hood knows. What Robin and his merry men carried on their backs were sheaves — bundles of arrows held in a handy little case called a quiver. After all, a sheaf of love letters or newspapers would make a pretty poor weapon against the evil Sheriff of Nottingham.