Endeka Kozanis is a traditional Greek dance, mostly danced at the region of Kozani. According to one point of view, it is a dance that was being danced at the weddings ("nyfiatikos" as said in Greek).
Some others say (which does not conflict with the first opinion above) that the dance took its name from the fact that when the Turks were established at the geographical terrain of Greece, the Greeks had to return to their homes not after eleven o'clock in the night. Of course, they spent even their last minute outside and used to return at exactly eleven o'clock, usually dancing this dance. That's why the dance is named Endeka; "endeka" means eleven in Greek.