(American)

1. to have sex (with). An American term which, apart from a brief vogue in the hippy era, has rarely been used in Britain or Australia. Originally an item of black argot, it gained wider popularity in the early 1960s and, as its anatomical origin suggests, is generally a male usage.

‘Presley fired me because I balled his old lady.’ (The singer P. J. Proby, interviewed in 1965)

2. to behave in a boisterous, fun-loving and uninhibited way; to ‘have a ball’. The term usually implies dancing, but also a degree of Bacchanalian, even orgiastic revelry far beyond that signified by the standard English (hunt or charity) ball.

‘Good golly, Miss Molly, you sure like to ball!’(Little Richard, [1] song lyrics, 1958)

3. to play basketball

4a. to behave ostentatiously

4b. to excel in a particular field. These senses of the word probably derive from black speech of the 1940s and later in which to ball meant to celebrate or enjoy oneself, itself influenced by the phrase ‘have a ball’.

As a noun: A stupid and/or obnoxious person. The slang for testicle has also been used as an insult by British junior-school pupils.