"round object," O.E., from O.N. bollr "ball," from P.Gmc. *balluz (cf. O.H.G. ballo, Ger. Ball), from PIE base *bhel- (2) "to swell" (see bole). The verb meaning "copulate" is first recorded 1940s in jazz slang. To be on the ball is 1912, from sports. Ball-point pen first recorded
1947. Ball of fire when first recorded in 1821 referred to "a glass of brandy;" as "spectacularly successful striver" it is c.1900. Ball and chain as a prisoner's restraint is recorded from 1835; as "one's wife," early 1920s.
"dancing party," 1630s, from Fr., from O.Fr. baller "to dance," from L.L. ballare "to dance," from Gk. ballizein "to dance, jump about" (see ballistics). Hence, "very enjoyable time," 1945, Amer.Eng. slang, perhaps back to 1930s in black slang.