A hackney or hackney carriage (also called a cab, black cab, hack or London taxi) is a carriage or automobile for hire. A hackney of a more expensive or high class was called a remise.
In the United Kingdom, the name hackney carriage today refers to a taxicab licensed by the Public Carriage Office, local authority (non-metropolitan district councils, unitary authorities) or the Department of the Environment depending on region of the country.
In the United States, the police department of the city of Boston has a Hackney Carriage Unit, analogous to taxicab regulators in other cities, that issues Hackney Carriage medallions to its taxi operators.
The name 'hackney' was once thought to be an anglicized derivative of French haquenée — a horse of medium size recommended for lady riders; however, current opinion is that it is derived from the village name Hackney (now part of London).
Despite the currency of this opinion, however, earlier sources dispute it. In 1908, a popular London newspaper stated, "The hackney coach—which is commonly supposed, though wrongly, to have taken its name from the district in the north of London—was started in the metropolis so long ago as 1025 by a certain Captain Bailey." The place-name, through its fame for its horses and horse-drawn carriages, is also the root of the Spanish word jaca, a term used for a small breed of horse and the Sardinian achetta horse. The first documented hackney coach—the forerunner of the more generic hackney carriage—operated in London in 1621. The New York City colloquial terms "hack" (taxi or taxi-driver), hackstand (taxi stand), and hack license (taxi license) are probably derived from hackney carriage. Such cabs are now regulated by the New York City Taxi and Limousine Commission.