Wiktionary
yekke
alt. (context mildly derogatory English) A Jew originating from Germany currently living in Israel. n. (context mildly derogatory English) A Jew originating from Germany currently living in Israel.
Wikipedia
Yekke
A yekke is a Jew of German-speaking origin. The term carries the connotation that German Jews are notable for attention to detail and punctuality.