Both of the things you said are bullshit.

1. Anti-semitism (anti-jewish racism) is real. To claim otherwise is to deny a whole history of atrocities, as well as ongoing phenomena. Random Jewish people even completely unrelated to anything to do with Israel are attacked all the time. Neofascists are using clear antisemitic tropes and dogwhistles, even when they are not straight up talking about Jewish space lasers putting fires in California.

2. Anti-semitism is the prejudice, systemic and personal, against Jews. While etymology sometimes can clarify nuances in meaning, it is not necessarily semantically meaningful. The word "semitic" is either an entirely linguistic one (semitic languages), i.e., narrowly technical in a scientific field, or it makes reference to outdated pseudo scientific racist theories, in a list that includes things like the Aryan race and the Mediterranean race.

Finally: bullshit like what you wrote is either perpetuated by bona fide antisemite fascists or by people who completely misguidedly think that this way they are somehow helping the Palestinian cause (they are not, in fact, they are hurting it).