Noun

1. A solid or hollow sphere.
2. An object, generally spherical, used for playing games.
3. A quantity of string, thread, etc., wound into a spherical shape.

   'ball' of wool

4. A pitch that falls outside of the strike zone.
5. An opportunity to launch the ball into play.
6. A solid, spherical nonexplosive missile for a cannon, etc.
7. A jacketed non-expanding bullet, typically of military origin.
8. The set of points in a metric space lying within a given distance (the radius) of a given point; specifically, the homologue of the disk in a Euclidean space of any number of dimensions.
9. The set of points in a topological space lying within some open set containing a given point; the analogue of the disk in a Euclidean space.
10. A testicle.
11. Nonsense.

    That’s a load of balls, and you know it! — Synonyms — See WikiSaurus:Nonsense

12. Courage.

    I doubt he’s got the balls to tell him off.

13. A single delivery by the bowler, six of which make up an over.
14. The ball of a foot

Synonyms

• sphere
• globe
• (testicle): See WikiSaurus:testicle
• (slang: courage) chutzpah, guts, nerve

Interjection

1. An appeal by the crowd for holding the ball against a tackled player. This is heard almost any time an opposition player is tackled, without regard to whether the rules about "prior opportunity" to dispose of the ball are fulfilled.

   2007: A good tackle (and some bad ones) will bring a cry of "Ball!" from the crowd – a plea for a holding the ball free kick. — AFL Sydney Swans Rules Zone http://www.afl.com.au/FanZone/Rules/tabid/7892/Default.aspx

Noun

1. A formal dance.
2. A very enjoyable time.

   I had a ball at that concert