By default, Drupal automatically generates pages for Taxonomy terms, which can get picked up by Google. If this is not desirable for your site, follow the steps below:
- Navigate to Structure, and then Pages.
- Find the system page called "Taxonomy term template" and click on the button Enable. The page will reload itself.
- Again, find the system page called "Taxonomy term template" and click on the button Edit.
- Click on the link Add new variant.
- A form will appear:
- Title: Enter an administrative title for the variant. For example, "404 page variant".
- Variant type: Select "HTTP response code".
- Optional features: Ignore these.
- Once done, click on the button Create variant.
- On the next page, set the Response code to "404 Page not found" and then click on Create variant.
- Lastly, click on the button Update and save.
Note: In the future, Taxonomy term pages may get disabled across the board, so these steps will no longer be necessary.