Nomenclature
Most of Ukraine's oblasts are named after their capital cities, officially referred to as "oblast centers" (Ukrainian: обласний центр, translit. oblasnyi tsentr). The name of each oblast is a relative adjective, formed by adding a feminine suffix to the name of respective center city: Sumy is the center of the Sums’ka oblast (Sumy Oblast). Most oblasts are also sometimes referred to in a feminine noun form, following the convention of traditional regional place names, ending with the suffix "-shchyna", as is the case with the Sumy Oblast, Sumshchyna.
See also: Romanization of UkrainianRead more about this topic: Sumy Oblast