A derrogatory terminology used by Coreans against the Japanese. Similar to saying "Japs" or "Nips". This is due to Japan's colonization and mass murder of Koreans prior to and during WWII.
Mr. Kim: Damn those jjokbari's are good customers. They buy so much rice and kimchee.
Mr. Kang: Yeah, jjokbari's are not only good customers, but their dingalings are smaller than Hangook Sarahm's jajee.