noun
A solid or hollow sphere, or roughly spherical mass.
(mathematics) Homologue or analogue of a disk in the Euclidean plane.
(ballistics, firearms) A solid, spherical nonexplosive missile for a cannon, rifle, gun, etc.
A roundish, protuberant portion of some part of the body.
The globe; the earthly sphere.
(sports, countable) An object that is the focus of many sports and games, in which it may be thrown, caught, kicked, bounced, rolled, chased, retrieved, hit with an instrument, spun, etc., usually roughly spherical or ovoid but whose size, weight, bounciness, colour, etc. differ according to the game
(mildly vulgar, slang, usually in the plural) A testicle.
(printing, historical) A leather-covered cushion, fastened to a handle called a ballstock; formerly used by printers for inking the form, then superseded by the roller.
(farriery, historical) A large pill, a form in which medicine was given to horses; a bolus.
(slang, countable, uncountable, singular only) One thousand US dollars.
verb
(transitive) To form or wind into a ball.
(metalworking) To heat in a furnace and form into balls for rolling.
(transitive, intransitive, US, vulgar) To have sexual intercourse (with).
(ambitransitive) To gather balls which cling to the feet or skis, as of damp snow or clay; to gather into balls.
(slang, usually in present participle) To be hip or cool.
(university slang) To reject from a fraternity or sorority. (Ellipsis of blackball).
(slang) To play basketball.
(African-American Vernacular) To spend money extravagantly.
(transitive) To punish by affixing a ball and chain.
(transitive) Of bees: to kill (a wasp) by surrounding it in large numbers so as to raise its body heat.
(intransitive) To operate (a vehicle) at high speed (whether balls-out, balls to the wall, or ballin' the jack, each of which comes ultimately from ball via a different route).
interjection
(sports) An exclamation to inform players on an adjacent playing area that a loose ball from another game has entered their playing area; typically implies that play should be paused until the ball has been retrieved.
(Australian rules football) An appeal by the crowd for holding the ball against a tackled player.
noun
A formal dance.
(informal) A very enjoyable time.
A competitive event among young African-American and Latin American LGBTQ+ people in which prizes are awarded for drag and similar performances. See ball culture.