ennui

I only recently learned the correct pronunciation of this word. It's one of those words that you run across in writing enough that you can figure out what it means from context, and you kind of come up with your own way to say it in your head, and maybe you heard it spoken before, too, but the spoken pronunciation was so different than the one you made up in your head that you didn't file it under the same word in that vocabulary file in your head. Other words in this category for me would be things like "hegemony" and "basalt". Is it buh-SALT? BAY-salt? Hmm, Merriam Webster says either is valid, but they both sound wrong. And dammit, I still think "incongruous" should be pronounced with the accent on the third syllable, not the second.

What words do you have in your vocabulary but not necessarily with the correct pronunciation?