A family of Microsoft word processing software products for creating web, email, and print documents.
See: Uninstall Office from a PC - Office Support
To reinstall, after uninstalling, Download and install or reinstall Office 365 or Office 2021 on a PC or Mac. So long as your subscription shows up as in force, this should be relatively straightforward.
(I updated the title in your post to include the error message in case anyone else runs into the same problem.)