Taxonomy description for a custom taxonomy view
Edit your taxonomy vocabulary.

Add the field (or fields) that you want. (Hint: The existing field named "Description" doesn't work, so create a new text-area field if that's what you want. I called my replacement field "Definition".)

From the List tab, edit each term's value for the new field.

Create a new view.

Show: Taxonomy terms of type: your_vocabulary, with a page display

Continue &amp; Edit

Configure the view to display only your new field(s).

Use pager: Display a specified number of items | 1 item

Add a Taxonomy Term contextual filter

Edit the existing Taxonomy Term view.

Click on the "add" button in the Header section

Select Global view type header

Select the new view you created above

Check the "Inherit contextual filters" checkbox

Now when you visit the Taxonomy Term view, your new fields view will be included at the top.