A jockey is someone who rides horses in horse racing or steeplechase racing, primarily as a profession. The word also applies to camel riders in camel racing.
The word is by origin a diminutive of "jock", the Northern English or Scots colloquial equivalent of the first name "John," which is also used generically for "boy, or fellow" (compare "Jack", "Dick"), at least since 1529. A familiar instance of the use of the word as a name is in "Jockey of Norfolk" in Shakespeare's Richard III. v. 3, 304.
In the 16th and 17th centuries the word was applied to horse-dealers, postilions, itinerant minstrels and vagabonds, and thus frequently bore the meaning of a cunning trickster, a "sharp", whence the verb to jockey, "to outwit", or "to do" a person out of something. The current usage which means a person who rides a horse in races was first seen in 1670.
Another possible origin is the Gaelic word eachaidhe, a "horseman", (pronounced YACH-ee-yuh in late medieval times, with the ch pronounced as in German). The Irish name "Eochaid" (YO-ked) is related to "each" (yek), horse, and is usually translated as "horse rider". This is phonetically very similar to "jockey"
Jockeys must be light to ride at the weights which are assigned to their mounts. There are horse carrying weight limits, that are set by racing authorities. The Kentucky Derby, for example, has a weight limit of 126 lb (57 kg) including the jockey's equipment. The weight of a jockey usually ranges from 108 to 118 lb (49 to 54 kg). Despite their light weight, they must be able to control a horse that is moving at 40 mph (64 km/h) and weighs 1,200 lb (540 kg). Though there is no height limit for jockeys, they are usually fairly short due to the weight limits. Jockeys typically stand around 4 ft 10 in (1.47 m) to 5 ft 6 in (1.68 m).
Jockeys are normally self employed, nominated by horse trainers to ride their horses in races, for a fee (which is paid regardless of the prize money the horse earns for a race) and a percentage of the purse winnings. In Australia, employment of apprentice jockeys is in terms of indenture to a master (a trainer); and there is a clear employee-employer relationship. When an apprentice jockey finishes their apprenticeship and becomes a "fully fledged jockey", the nature of their employment and insurance requirements change because they are regarded as "freelance", like contractors. Jockeys often cease their riding careers to take up other employment in racing, usually as trainers. In this way the apprenticeship system serves to induct young people into racing employment.