Ball of the foot dates from the 14th century and, unless your feet at very flat, there is a certain rounded shape to that part.
Ball point pen is first seen in 1946, and it does describe the pen rather well.
Ball of fire is not quite what you might think, for when first recorded in 1821 it referred to a glass of brandy; latterly used to refer to one who is highly successful in striving for success from around 1900.
On the ball, as in to perform rather well, is seen from 1912.
To keep your eye on the ball, which seems to me a rather wordy way to describe concentration, is first seen in 1907 and thought to be derived from golf.
To have the ball, an expression meaning to hold an advantage, is not particularly popular today but must have been when first recorded around 1400.
The ball was never in your court before 1956, although this tennis reference could well be much earlier as the name was played for centuries.
Ballcocks, useful in plumbing disasters to shut off the water, is a term used since 1790.
Puff ball, an accurate description of how this fungus distributes spores, has been found in print as early as 1640.
Stoolball, a game you probably have never heard of before, was an outdoor game similar to cricket. Played by women from the late 15th century, the 'stool' was the wicket and it seems likely the wicket used an actual stool.
Ball boy has been used to describe the laddie who retrieves tennis balls since 1896. Ball girls had to wait until 1953 before getting a mention, although girls were used from 1920.
Ballbearings are used to reduce friction in mechanisms, the term first used in 1874.
Ballrooms are designed for dancing, if you like that sort of thing, the term first documented in 1724. However, while we associate ballroom dancing with ballrooms, ballroom dancing is not recorded until 1872.
Mothballs, despite the very old and very bad joke, were used to deter moths from laying their eggs on our clothes. The term is first recorded in 1891.
And we can't go without giving some earliest dates for ball sports where, like football, 'ball' is a part of the name: football is found in a document from around 1400, and again in 1424 (where the reference bans the game); volleyball in 1896; racquetball from 1972; handball as early as 1885 (albeit a different game was also known as handball in the 15th century); basketball dates from 1892; and baseball from 1845.
