What is Borough?

Legal Definition
A borough is an administrative division in various English-speaking countries. In principle, the term borough designates a self-governing walled town, although in practice, official use of the term varies widely.

The word borough derives from common Germanic *Burg, meaning fort: compare with bury, burgh and brough (England), burgh (Scotland), Burg (Germany), borg (Scandinavia), burcht (Dutch), boarch (West Frisian), and the Germanic borrowing present in neighbouring Indo-european languages such as borgo (Italian), bourg (French), burgo (Spanish and Portuguese), burg (Romanian), purg (Kajkavian) and durg (दर्ग) (Hindi) and arg (ارگ) (Persian). The incidence of these words as suffixes to place names (for example, Aldeburgh, Bamburgh, Tilbury, Tilburg, Strasbourg (Strossburi in the local dialect), Luxembourg, Edinburgh, Grundisburgh, Hamburg, Gothenburg) usually indicates that they were once fortified settlements.

In the Middle Ages, boroughs were settlements in England that were granted some self-government; burghs were the Scottish equivalent. In medieval England, boroughs were also entitled to elect members of parliament. The use of the word borough probably derives from the burghal system of Alfred the Great. Alfred set up a system of defensive strong points (Burhs); in order to maintain these settlements, he granted them a degree of autonomy. After the Norman Conquest, when certain towns were granted self-governance, the concept of the burh/borough seems to have been reused to mean a self-governing settlement.

The concept of the borough has been used repeatedly (and often differently) throughout the world. Often, a borough is a single town with its own local government. However, in some cities it is a subdivision of the city (for example, New York City, London, and Montreal). In such cases, the borough will normally have either limited powers delegated to it by the city's local government, or no powers at all. In other places, such as the U.S. state of Alaska, borough designates a whole region; Alaska's largest borough, the North Slope Borough, is comparable in area to the entire United Kingdom, although its population is less than that of Swanage on England's south coast with around 9,600 inhabitants. In Australia, a borough was once a self-governing small town, but this designation has all but vanished, except for the only remaining borough in the country, which is the Borough of Queenscliffe.

Boroughs as administrative units are to be found in Ireland and the United Kingdom, more specifically in England and Northern Ireland. Boroughs also exist in the Canadian province of Quebec and formerly in Ontario, in some states of the United States, in Israel, formerly in New Zealand and only one left in Australia.
-- Wikipedia
Legal Definition
An incorporated town; so called in the charter. It is less than a city. 1 Mann. & Gran. 1; 39 E. C. L. R. 323.
-- Bouviers Law Dictionary
Legal Definition
In English law. A town, a walled town. Co. Litt 108b. A town of note or importance; a fortified town. Cowell. An ancient town. Litt. 164. A corporate town that is not a city. Cowell. An ancient town, corporate or not, that sends burgesses to parliament. Co. Litt. 109a; 1 Bl. Comm. 114, 115. A city or other town sending burgesses to parliament. 1 Steph. Comm. 116. A town or placo organised for local government. A parliamentary borough is a town which returns one or more members to parliament.

In Scotch law. A corporate body erected by the charter of the sovereign, consisting of the inhabitants of the territory erected into the borough. Bell.

In American law. In Pennsylvania, the term demotes a part of a township having a charter for municipal purposes; and the same is true of Connecticut. Southport v. Ogden, 23 Conn. 128. See, also, 1 Dlll. Mun. Corp. § 41,

n. "Borough" and "village" are duplicate or cumulative names of the same thing; proof of either will sustain a charge in an indictment employing the other term. Brown v. State, 18 Ohio St. 496.
-- Black's Law Dictionary
Legal Definition
A fortified town; a municipal corporation. See Ann. Cas. 1912A, 339.
-- Ballentine's Law Dictionary