a) A surface created by projecting a closed two-dimensional curve along an axis intersecting the plane of the curve.
When the two-dimensional curve is a circle, the cylinder is called a circular cylinder. When the axis is perpendicular to the plane of the curve, the cylinder is called a right cylinder. In non-mathematical usage, both right and circular are usually implied.
b) A solid figure bounded by a cylinder and two parallel planes intersecting the cylinder.
A big greyish rounded bulk, the size, perhaps, of a bear, was rising slowly and painfully out of the cylinder.
See Also: cylindrical
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