Meaning wanker. The most common offensive verbal abuse especially if you add a certain gesture. Otherwise it's rather mild. It is even used in a tender, softer spoken way among friends or as "dude" among colleagues. It is not used in a friendly way in football or traffic though.
Christos Kalloniatis (Professor of the Department of Cultural Technology and Communication at the University of the Aegean), Iris Kritikou (Archaeologist-Historian of Art), Konstantinos Maniatopoulos (Director of the Stratis Eleftheriadis-Tériade Museum – Library, Visual Artist-Historian of Art), Irine Vasilopoulou