An administrative unit of a city which, under most circumstances according to state or national law, would be considered a larger or more powerful entity; most commonly used in American English to define the five counties that make up New York City
A borough is a town, or a district within a large town, which has its own council. the New York City borough of Brooklyn. a town, or part of a large city, that is responsible for managing its own schools, hospitals, roads etc
In England, an incorporated town that is not a city; also, a town that sends members to parliament; in Scotland, a body corporate, consisting of the inhabitants of a certain district, erected by the sovereign, with a certain jurisdiction; in America, an incorporated town or village, as in Pennsylvania and Connecticut