You can delete any facet in the Facets tree. Deleting a facet from a shared catalog or category deletes it from all shared locations. Deleting a parent facet also deletes its children. Deleting a child facet does not affect its parents.
To delete a facet:
In a Merchandising project, navigate to Search Merchandising and show Facets.
In the Navigation pane, click the check box next to the facet that you want to delete.
Click the Delete icon.
Click OK in the confirmation dialog to delete the facet or click Cancel to leave the facet unchanged.