We have all done it, you are trying to correct a misspelled word and rather than clicking the corrected spelling we click add to dictionary. Okay, maybe not everyone has done this but the other day I did it to myself in Microsoft Teams.
I thought this would be a quick fix. I would go to Word and edit the custom dictionary for Word and all would be forgotten. Unfortunately, the Microsoft Word custom dictionary for Teams.
I then went to the dictionary for Chrome (since Teams is an Electron app). This was also not the location my ariently placed word.
I did find it after some digging. The Teams Custom Dictionary file is in /Users/[user_name]/Library/Application Support/Microsoft/Teams. The file is called "Custom Dictionary.txt". All you have to do is edit the error out of the dictionary and all is well.