a spherical or approximately spherical body or shape; sphere

He rolled the piece of paper into a ball.

a round or roundish body, of various sizes and materials, either hollow or solid, for use in games, as baseball, football, tennis, or golf.

a game played with a ball, esp. baseball

The boys are out playing ball.

Baseball . a pitched ball, not swung at by the batter, that does not pass over home plate between the batter's shoulders and knees.

Military .

a solid, usually spherical projectile for a cannon, rifle, pistol, etc., as distinguished from a shell.

projectiles, esp. bullets, collectively.

any part of a thing, esp. of the human body, that is rounded or protuberant

the ball of the thumb.

a round mass of food, as of chopped meat, dough, or candy.

Slang

Vulgar a testis.

balls, Slang

Vulgar

boldness; courage; brashness.

nonsense (often used as an interjection).

bolus ( def. 1 ) .

Horticulture . a compact mass of soil covering the roots of an uprooted tree or other plant.

Literary . a planetary or celestial body, esp. the earth.

Mathematics . (in a metric space) the set of points whose distance from the zero element is less than, or less than or equal to, a specified number.

to make into a ball (sometimes fol. by up )

The children were balling up snow to make a snowman.

to wind into balls

to ball cotton.

Slang

Vulgar to have sexual intercourse with.

to form or gather into a ball

When the spun sugar balls, the candy has cooked sufficiently.

Slang

Vulgar to have sexual intercourse.

ball up, Slang . to make or become utterly confused; muddle

The records had been all balled up by inefficient file clerks.

ball the jack

Slang .

to act with speed.

to stake everything on one attempt.

carry the ball

to assume the responsibility; bear the burden

You can always count on him to carry the ball in an emergency.

drop the ball

to make a mistake or miss an opportunity at a critical moment.

keep the ball rolling

to continue or give renewed vigor to an activity already under way

When their interest lagged, he tried to keep the ball rolling.

on the ball

alert and efficient or effective

If you don't get on the ball, you'll be fired.

indicating intelligence or ability

The tests show your students don't have much on the ball. The new manager has a lot on the ball.

play ball

to begin or continue playing a game.

to start or continue any action.

to work together; cooperate

union leaders suspected of playing ball with racketeers.

run with the ball

to assume responsibility or work enthusiastically

If management approves the concept, we'll run with the ball.

start the ball rolling

to put into operation; begin

The recreation director started the ball rolling by having all the participants introduce themselves.

verb

blunder , boggle , bungle , foul up , fumble , gum up , mess up , mishandle , mismanage , muddle , muff , spoil , disorder , jumble , scramble , snarl