A word used to describe the fascist tendencies of certain jews who, for instance, try to stifle all criticism of israel/judaism by crying 'anti-semitism'. Or jews who believe that non-jews are not as human as jews, etc.
Sometimes used as a slur by people who are genuinely anti-semitic.
"I disagree with some policies of Israel"
"This is anti-semitic Islamofascism!!!"
"No. But maybe you are showing signs of Judeofascism."