There is no historical documents which point to the origin of the village name. In time three popular theories developed, none of which is taken seriously in consideration. One myth claims that Despot Stefan Lazarević, who died somewhere on the Kosmaj mountain, suffered a death rattle on this location (Serbian ropac). Another jovial story claims the same word origin, but regarding some local Turkish pasha. Third was laid by professor Milivoj Pavlović in his 1969 article From Singidunum to Kosmaj. He claimed the name is of Celtic origin. The Serbs mixed with the local Celtic population and named the locality arp, Celtic word for the slope, which in time molded into rop.