On most apps that you can paste text in, you can remove the formatting with the Ctrl+Shift+V keyboard shortcut. In Word, this shortcut does nothing however, if you’d like to use it to paste text without formatting, you can set it up to do so.
Open Word and go to File>Options. Select the Customize Ribbon tab. At the bottom, you will see ‘Keyboard options’. Click the ‘Customize’ button next to it. In the new window that opens, look for ‘All Commands’ in the Categories column. Select it and then move to the column on the right. The commands here are sorted alphabetically. Select ‘PasteTextOnly’.
Once selected, click inside the ‘Press new shortcut key’ field and tap the Ctrl+Shift+V keyboard shortcut. You can use any other shortcut if you want, just make sure it doesn’t clash with other shortcuts. Click Assign and close the window.