What is the origin of the word "handicap"?

A handicap is a race or contest in which an artificial advantage is given, or disadvantage imposed, on a contestant to equalise chances of winning.

The term “handicap” derives from the expression “hand in cap.” However, this does not refer to maimed veterans of war, who were granted the right to beg on the streets on London, with cap in hand. "Handicap," which has been in use since the middle of the 17th century, comes from the name of a game that involved two players, one umpire, a hat, and some hands. Players placed bets or money into the cap of a neutral arbiter to reach an agreement as to the relative values of items sought to be traded.

The word progressed from one sport to another, and by the middle of the 18th century it began to be used in horse-racing, in reference to additional weight borne by a horse thought to otherwise have an advantage. From horse-racing the word spread to other sports, such as golf, and from there began to be used to refer to any encumbrance. It was not until the end of the 19th century that the term “handicap” was used to refer specifically to a physical disability.