First I would like to begin this thread by saying that it is being posted to explain the definition and origin of the term "antisemitism" and not a way to say it exists here in DU or to accuse anybody of antisemitism. So there is no need for anybody to be on the defensive.
I felt the need to post this here since there is a controversy here when we have discussions where many here argue that anti-Arab sentiments or hatred against Arabs is synonym with antisemitism using the logic that since Jews and Arabs are both Semites therefore anti-Arab equals antisemitism.
Many people don't know that the word "ANTISEMITISM" was coined by Wilhelm Marr, an antisemite himself. Ironically, Wilhelm Mars created the expression "antisemitism" in 1879 with the intention to be known among all future antisemites as a leader of a powerful movement of Jew-haters but today he is only known to Jewish scholars.
Marr wanted to replace the German word "judenhass" (Jew-hatred) with a word that would make Jew-haters sound less vulgar and even somewhat scientific.
The problem is that the term he created is misleading since it conveys the impression that antisemites oppose Semites. This has enabled Jew-haters in the Arab world to deny they are antisemites, on the eminently logical grounds that they are themselves Semites. But for Marr, Hitler, and other Jew-haters, the term "antisemitism" has always been a code word used exclusively against Jews.
Hitler himself had not compunctions about welcoming (Semitic) Arab leaders, including the Mufti of Jerusalem, to Berlin during World War II. For this reason, many writers today have adopted the practice initiated by several Jewish and Christian scholars and write antisemitism as one word. Spelling antisemitism as "anti-Semitism" in the conventional manner, only fosters the false impression that there is a wider ethnic entity against which "anti-Semitism" is leveled.
Throughout history, antisemitism has been directed against Judaism and its values.
The term "antisemitism" defined by the The American Heritage Dictionary of the English Language:
an·ti-Sem·i·tism (n.)
1. Hostility toward or prejudice against Jews or Judaism.
2. Discrimination against Jews.
The term "antisemitism" defined by WordNet 2.0, © 2003 Princeton University:
antisemitism
anti-Semitism n : the intense dislike for and prejudice against Jewish people