Ukrainians (Ukrainian: українці, ukrayintsi, [ukrɑˈjinʲtsʲi]) are an East Slavic ethnic group native to Ukraine, which is by total population the sixth-largest nation in Europe. The Constitution of Ukraine applies the term 'Ukrainians' to all its citizens. Also among historical names of the people of Ukraine, Rusyns (Ruthenians), Cossacks, etc. can be found. According to most dictionary definitions, a descriptive name for the "inhabitants of Ukraine" is Ukrainian or Ukrainian people. Rusyns are another related group found in western Ukraine, which are frequently referred to as being an ethnic subgroup of Ukrainians. The Rusyns are also further divided into subgroups of tribes consisiting of the Hutsuls, Boykos, and Lemkos.