Delete currently open article
Right-click the root of the article tree. Select Delete article.
Delete an article in the list of articles
Right-click it and then select Delete. Note: you can delete only articles that are not published and not linked to pages (unpublish/unlink first and then spike).
Note
In older configuration delete may be called "Spike". The deleted content is moved in the Trash can from where it can be restored until it gets automatically purged (usually after 72 hours or so).
To learn more, see also