Kosovo - Wikipedia The name Kosovo is of South Slavic origin Kosovo (Косово) is the Serbian neuter possessive adjective of kos (кос), ' blackbird ', [19][20] an ellipsis for Kosovo Polje, 'Blackbird Field', the name of a karst field situated in the eastern half of today's Kosovo and the site of the 1389 Battle of Kosovo Field [21] In the Middle Ages, territory to the west of Kosovo was known as