Uwabaki
I had never heard the word "uwabaki" until only a year or so ago. Also, I used to think "uwagutsu" (上靴, lit. "indoor/upper shoes") was "wa-gutsu" (和靴, "Japanese shoes"). An honest mistake.
The Japanese people have a bad habit of not correcting the broken Japanese of foreigners which really isn't very helpful in the long run.
Case in point, I met a German woman some years ago who I noticed was writing her name in katakana (カタカナ) in correctly. She was shocked to find out because I was the first person to point it out despite her mis-writing her name for almost a decade. She was mortified to learn this, but less so than if she had been making the mistake for 20 years rather than 10.
I guess the lesson here is, when in doubt look things up for yourself. The Internet is there for a reason.