The word "Usumbura" refers to a specific place, which is the capital and largest city of Burundi, a country in East Africa. However, it's important to note that Usumbura was renamed "Bujumbura" when Burundi gained independence in 1962.
In more advanced discussions, you might encounter references to Usumbura in historical texts or discussions about colonialism and the history of Burundi.
In summary, Usumbura is the former name of Bujumbura, the capital city of Burundi, and is primarily used in historical contexts.