Round

Round is a term with multiple related meanings across geometry, measurement, and everyday language. In geometry, a round object is roughly circular in outline, having no sharp corners and an approximately uniform distance from its center. The word derives from Old French ronde and Latin rotundus, reflecting a curved form.

In mathematical usage, round typically refers to a circle: all points at a fixed distance, the radius, from a center. The circle’s circumference is 2πr, and its area is πr^2. A diameter d equals 2r. A round or circle is the simplest closed curve in the plane.

Rounding in arithmetic is the process of approximating a number by replacing it with a value that has fewer or simpler digits. Common methods include rounding to the nearest unit, tenth, or integer, often using round half up. Other modes include rounding toward zero, toward positive infinity, or toward negative infinity, and banker's rounding used in financial calculations.

Round also denotes a sequence of related items or events, such as a round of golf, a round of drinks, a round in a game or tournament, or a round of ammunition. Each round represents one occurrence or set within a larger series.

In music, a round is a form of canon in which different voices sing the same melody starting at successive times, creating overlapping, imitative lines. A well-known example is Row, Row, Row Your Boat.

As a verb, round means to move along a curve, to bring something to a curved edge, or to complete by adding a curved finishing touch (rounding off). It is also used in phrases describing roundness or rounded shapes.