handicapyoudaoicibaDictYouDict[handicap 词源字典]
handicap: [17] The word handicap originally denoted a sort of game of chance in which one person put up one of his or her personal possessions against an article belonging to someone else (for example one might match a gold watch against the other’s horse) and an umpire was appointed to adjudicate on the respective values of the articles. All three parties put their hands into a hat, together with a wager, and on hearing the umpire’s verdict the two opponents had to withdraw them in such a way as to indicate whether they wished to proceed with the game.

If they agreed, either in favour of proceeding or against, the umpire took the money; but if they disagreed, the one who wanted to proceed took it. It was the concealing of the hands in the hat that gave the game its name hand in cap, hand i’ cap, source of modern English handicap. In the 18th century the same term was applied to a sort of horse race between two horses, in which an umpire decided on a weight disadvantage to be imposed on a superior horse and again the owners of the horses signalled their assent to or dissent from his adjudication by the way in which they withdrew their hands from a hat.

Such a race became known as a handicap race, and in the 19th century the term handicap first broadened out to any contest in which inequalities are artificially evened out, and was eventually transferred to the ‘disadvantage’ imposed on superior contestants – whence the main modern meaning, ‘disadvantage, disability’.

[handicap etymology, handicap origin, 英语词源]
handicap (n.)youdaoicibaDictYouDict
1650s, from hand in cap, a game whereby two bettors would engage a neutral umpire to determine the odds in an unequal contest. The bettors would put their hands holding forfeit money into a hat or cap. The umpire would announce the odds and the bettors would withdraw their hands -- hands full meaning that they accepted the odds and the bet was on, hands empty meaning they did not accept the bet and were willing to forfeit the money. If one forfeited, then the money went to the other. If both agreed either on forfeiting or going ahead with the wager, then the umpire kept the money as payment. The custom, though not the name, is attested from 14c. ("Piers Plowman").

Reference to horse racing is 1754 (Handy-Cap Match), where the umpire decrees the superior horse should carry extra weight as a "handicap;" this led to sense of "encumbrance, disability" first recorded 1890. The main modern sense, "a mental or physical disability," is the last to develop, early 20c.
handicap (v.)youdaoicibaDictYouDict
"equalize chances of competitors," 1852, but implied in the horse-race sense from mid-18c., from handicap (n.). Meaning "put at a disadvantage" is from 1864. Earliest verbal sense, now obsolete, was "to gain as in a wagering game" (1640s). Related: Handicapped; handicapping.