A bairro (lit. quarter, Portuguese pronunciation: [ˈbajʁu]) is a community or region within a city or municipality of Brazil, Mozambique, Guinea-Bissau, or some of Portugal. Regions referred to as bairros exist in most major Brazilian cities. Related English words include: "neighborhood" or "district" and "borough" or "subdivision". "Bairro" as a Portuguese word is cognate with Germanic berg, burg, borg, burgh, borough (etc.) and Spanish barrio, all of which descend from the same Proto-Indo European root.
In Brazil, the word is frequently applied to urban areas in cities, in which the bairros are generally defined only unofficially and have rough borders, without any official administrative function. In some cities, however, the bairros have defined territorial limits set by the municipal government, but most follow popular definition by its citizens.
In Portugal, subdivisions in only a few densely populated urban regions are called bairros, though these do not have any administrative power. An example is the Bairro Alto in Lisbon. The word "freguesia" names the more common subdivisions in Portugal.
In Mozambique, bairros are administrative subdivisions of urban districts with important functions in the identification of the residents and determine the attributes of the area in regard to construction or agriculture, much like zoning. They are directed by secretários.
In Guinea-Bissau, bairros are first of all the peri-urban quarters of the capital Bissau beyond the old city centre (Praça), e.g. Bairro de Ajuda, Bairro Militar, Pessak, Quelele, Luanda, Mpantcha, and by extension quarters of smaller towns throughout the country.