Alright everybody, it’s time for the second installment of our nation's favorite series. Those who know me have probably figured for a long while now it was only a matter of time until I brought this up, so here goes…
The name of our religion is Judaism. That’s pronounced JUDAH-ism.
The proper pronunciation is “JUDAH-ism”, with the emphasis being on the first syllable. So: “JEW-dah-ism”.
We are named, ultimately, after a man by the name of Judah. Thus, Judaism. Simple. It’s amazing how widespread the mispronunciation has become. And I’m not even sure why. It’s not easier to say, now can it be really said that it is an Americanization of the word. I suppose it’s just developed over time from imprecision when speaking — which is of course only natural, but now that you know the proper pronunciation, you have no excuse.
UPDATE: I would like to just add here, in response to the comments section (which is recommended reading), that both Oxford and Merriam-Webster have Judah-ism as the correct pronunciation. (Okay, Oxford seems to lean a bit more towards Ju-DAY-ism, but that's only for the British pronunciation — and it's definitely not Ju-DEE-ism.)