Yeah, technically that's correct,in that the biblical Semites spoke that language.   However, you DO know,as does everybody or most people that antisemitic means anti-Jewish (as in the people of the Jewish faith/religion.  Even though Arabic peoples are also of a Semitic background, the term anti-semitic does NOT include the notion of anti-Arab.   Antisemitic (and you can look it up in any good dictionary, but  you already knew this...you are just being ridiculous for the sake of argument), means, and I repeat ANTI-JEWISH.   As in, people who dislike or hate Jews, are anti-Semitic.  I think the term is  quite clear to most, unless you are attempting to reinvent the wheel or something like that.

Gene