A family of Microsoft word processing software products for creating web, email, and print documents.
Let me explain what is going on.
When you open a password protected Word or Excel file on Android Word or Excel,
It opens the file and then dumps an unprotected version of that file deep into Android's file system.
Later, when you delete the original on your phone, the file still shows up in your Android Word or Excel 'recents' list and you can just tap it and open it. It is quite disturbing. It has a long file path usually users>>data>>0 ...
The only way to delete this copy is to go to Androids app screen, select Word or Excel > More Info > Storage > CLEAR DATA.
This will clear that folder with these files and reset your app. You do not have access to that folder to delete these files individually, this is the only way. Unfortunately, once you open another password protected file, it will again end up in this deep sub-folder and always be in your recent list ready to be opened sans password.
This is horrible oversight on behalf of MS and I must say, as a user of both Android and iOS, this problem does not exist on either the Word version for iOS, and definitely does not happen with any files created, opened, handled by Pages or Numbers, which is Apple's version of Word and Excel. The devil is in the details and this is why I rarely like to trust MS or Android with sensitive info.
* NOTE: The "remove fom list" option does not delete the file from the device. It will remain in that folder just no longer in the list .