Okrug

Okrug (, ; ; , ; ; ; ; ; , ) is an administrative division of some Slavic states. The word "okrug" is a loanword in English, but it is nevertheless often translated as "area", "district", or "region". 
Etymologically, "okrug" literally means "circuit". In meaning, the word is similar to the German term "Bezirk" ("district") and the French word "Arrondissement"; all of which refer to something "encircled" or "surrounded".
Bulgaria.
In Bulgaria, "okrаgs" are the abolished primary unit of the administrative division and implied "districts" or "counties". They existed in the post-War Bulgaria between 1946 and 1987 and corresponded approximately to today's oblasts.
Poland.
As historical administrative subdivisions of Poland, okręgi existed in the later part of the Congress Poland period, from 1842, when the name was applied to the former powiats (the name "powiat" being transferred to the former "obwody"). See Administrative division of Congress Poland.
Okręgi were also created temporarily from 1945 to 1946, in the areas annexed to Poland from Germany as a result of the Soviet military advance. An okręg was then subdivided into obwody. These okręgi were later replaced by voivodeships, and the obwody by powiats.
Russia.
Imperial Russia.
"Okrugs" were one of the several types of administrative division for oblasts and selected governorates in Imperial Russia. Until the 1920s, "okrugs" were administrative districts in Cossack hosts such as the Don Cossacks.
Soviet Union.
Inherited from the Imperial Russia, in the 1920s, "okrugs" were administrative divisions of several other primary divisions such as oblasts, krais, and others. For sometime in the 1920s they also served as the primary unit upon the abolishment of guberniyas and were divided into raions. On July 30, 1930 most of the okrugs were abolished. The remaining okrugs were phased away in the Russian SFSR during 1930–1946, although they were retained in Zakarpattia Oblast of the Ukrainian SSR in status equivalent to that of a raion.
"National okrugs" were first created in the Mountain ASSR of the Russian SFSR in 1921 as units of the Soviet autonomy and additional national okrugs were created in the Russian SFSR for the peoples of the north and Caucasus region. In 1977, all national okrugs were renamed "autonomous okrugs".
Russian Federation.
In the present-day Russian Federation, the term "okrug" is either translated as "district" or rendered directly as "okrug", and is used to describe the following types of divisions:
After the series of mergers in 2005–2008, several autonomous okrugs of Russia lost their federal subject status and are now considered to be administrative territories within the federal subjects they had been merged into:
"Okrug" is also used to describe the administrative divisions of the two "federal cities" in Russia:
In the federal city of Sevastopol, municipal okrugs are a type of a municipal formation.
In Tver Oblast, the term "okrug" also denotes a type of an administrative division which is equal in status to that of the districts.
Furthermore, the designation "okrug" denotes several "selsoviet"-level administrative divisions:
In some cities, the term "okrug" is used to refer to the administrative divisions of those cities. "Administrative okrugs" are such divisions in the cities of Murmansk, Omsk, and Tyumen; "city okrugs" are used in Krasnodar; "municipal okrugs" are the divisions of Nazran; "okrugs" exist in Belgorod, Kaluga, Kursk, and Novorossiysk; and "territorial okrugs" are the divisions of Arkhangelsk and Lipetsk.
The term "okrug" is also used to describe a type of a municipal formation, the "municipal urban okrug"—a municipal urban settlement not incorporated into a municipal district.
Serbia.
The Republic of Serbia is divided into twenty-nine "okrugs" as well as the City of Belgrade. The term "okrug" in Serbia is often translated as either "district" or "county".