Clayton,
We've been on different sides in many threads. But this is one of the simplest I've seen.
You asked in the OP, "Why are the Jews the only people, that I know of, who have a derogatory word for people who are not Jewish?"
Three pages of replies have provided long lists of people who have derogatory words for those outside their own group, including Christians, Muslims, Mormons, Scientologists, Romany, and even Nazis (surprise)!. Perhaps the impossible challenge would be to name a group of people who didn't have such words. And I assure you that the use of Goy among Jews is looked down on by most Jews, and is no more common than is the use of these other derogatory words in these other groups.
You then asked, "Why are the Jews the only people, that I know of, who have a word for people who supposedly hate them? antisemitic" If it were true, I would suggest that it might arise from encountering people who believe that only Jews have derogatory words for people who are not Jews. But more so, it's obviously not true (even ignoring the fact that anti-Semitic applies to many non-Jews as well). Google anti-Christian, anti-Muslim, anti-Black, anti-Asian... Do these terms not exist? Have the targets of these prejudices never felt these bigotries, nor fought back against them?
You responses so far- laughter, a repeat of your OP, and links to definitions that, even when quote-mined, only further disprove your assertion.
Come on, for once you can gain a little respect by just admitting you were wrong. Something like "Gee, I' sorry, I'm not sure what I was thinking. I still don't like Jews [you can use Zionists if you prefer] but my OP was factually incorrect and I see that now." Try it- be a mench!