Rant. In my regional accent, the A sound is different in words like ant and aunt, can and can't, bat and bath, plan and plant. So when it comes to ran and rant, my brain wants them to be pronounced differently too, but even in my region they're supposed to have the same sound. It's rare for me to use the word rant, so when I do, I have to be careful not to embarrass myself by saying it wrong. Probably why I rarely say it.

Just did a quick search, and I'm relieved to see there are other weird people out there like me with the same problem https://www.reddit.com/r/CasualUK/comments/7jw53e/how_do_you_pronounce_the_word_rant/