Semite, (or more properly, Semitic), applies to languages, not peoples. The term "anti-semitism" got coined in the 1870's because German bigots wanted their Jew-hate to have a scientific coat of paint. "Hebrew" is less common, but can refer to Jews, but mostly refers to the language, and Jews don't typically refer to ourselves as Hebrews. This was different 2,000 years ago, which is why the New Testament book is called Hebrews and not Jews. Personally I prefer to use "Jew-hate" instead of "antisemitism" because I hate euphamisms, especially when they're used to try to sugar coat things like this.