Milos Obilic (Serbian Cyrillic: Milosh Obilitsh, pronounced [miloS obilitc]; died June 15, 1389) was a Serbian knight in the service of Prince Lazar, during the invasion of the Ottoman Empire. He is not mentioned in contemporary sources, but he features prominently in later accounts of the Battle of Kosovo as the assassin of the Ottoman sultan Murad I. Although the assassin remains anonymous in sources until the late 15th century, the dissemination of the story of Murad's assassination in Florentine, Serbian, Ottoman and Greek sources suggests that versions of it circulated widely across the Balkans within half a century after the event. It is not certain whether Obilic actually existed, but Lazar's family - strengthening their political control - "gave birth to the myth of Kosovo", including the story of Obilic.

The hero's first name, Milos, is a Slavic given name recorded from the early Middle Ages among the Bulgarians, Czechs, Poles and Serbs. It is derived from the Slavic root mil-, meaning "merciful" or "dear", which is found in a great number of Slavic given names.  Several versions of the hero's surname have been used throughout history. In his History of Montenegro (1754), Vasilije Petrovic wrote of one Milos Obilijevic, and in 1765, the historian Pavle Julinac rendered the surname as Obilic. According to Czech historian Konstantin Josef Jirecek, the surname Obilic and its different renderings are derived from the Serbian words obilan ("plenty of") and obilje ("wealth, abundance"). The surname Kobilic could come from the Slavic word kobila (mare), and means "mare's son", as in Serbian legends the hero is said to have been nursed by one. K. Jirecek connected the surname to two noble families in medieval Ragusa and Trebinje, the Kobilic and Kobiljacic in the 14th and 15th centuries, and noted that they altered their surnames in the 18th century because they considered it "indecent" to be associated with mares. Based on a 1433 document from Ragusan archives, the historian Mihailo Dinic concluded that Milos's original surname was indeed Kobilic (Latin: Cobilich). The rendering Obilic has universally been used by Serbian writers in modern times.  The historian Noel Malcolm has proposed that the surname may have been derived from the term kopil, of possible Vlach or Albanian origin, which means "child" or "bastard child". However, a similar word (kopile) exists in the Serbian language and carries the same meaning. Malcolm also hypothesizes that Kobilic might be of Hungarian origin, possibly a transliteration of the Hungarian word kobor lovag (knight-errant).  Milos is often referred to in the epic poems as "Milos of Pocerje", and according to local legends, he came from the western Serbian region of Pocerina. In Pocerina there is a spring known as "Miloseva Banja" (Milos's spring) and an old grave that is claimed to be the grave of Milos's sister. Answer this question using a quote from the following article:

How did he get his name
The hero's first name, Milos, is a Slavic given name recorded from the early Middle Ages among the Bulgarians, Czechs, Poles and Serbs.