ball

1. A solid or hollow sphere, or roughly spherical mass. (countable, uncountable) · a ball of spittle; a fecal ball
2. A quantity of string, thread, etc., wound into a spherical shape. (countable, uncountable) · a ball of wool; a ball of twine
3. A food preparation formed into a spherical shape. (countable, uncountable) · This dish is served with balls of potato.
4. In 3-dimensional Euclidean space, the volume bounded by a sphere. (countable, uncountable)
5. The set of points in a metric space of any number of dimensions lying within a given distance (the radius) of a given point. (countable, uncountable)
6. The set of points in a topological space lying within some open set containing a given point. (countable, uncountable)
7. A jacketed non-expanding bullet, typically of military origin. (countable, uncountable)
8. A roundish, protuberant portion of some part of the body. (countable, uncountable) · the ball of the thumb

Plural balls