Wiktionary
agin-buryat autonomous okrug
n. (context historical English) an autonomous okrug of the Soviet Union and Russia with a center at Aginskoye; now part of Agin-Buryat Okrug
Wikipedia
Agin-Buryat Autonomous Okrug
Agin-Buryat Autonomous Okrug was an autonomous okrug of Russia. The okrug was completely surrounded by Chita Oblast.
On March 1, 2008, the oblast and the okrug merged to form Zabaykalsky Krai. The territory of the former autonomous okrug is now administrated as Agin-Buryat Okrug of Zabaykalsky Krai.