File - SharePoint - Discard Check Out

Ribbon bar. Select the Home tab. In the SharePoint group, click Discard to discard edits and undo the SharePoint document check out.

Classic menus. From the File - SharePoint submenu, select Discard Check Out to discard edits and undo the SharePoint document check out.

Note that you must have created a Web Folder to the SharePoint server location, and opened a document in SharePoint via the Open dialog box for this option to be available.