How to delete the site in Sharepoint 2013 completely?

Delete a SharePoint Server site or subsite:
Navigate to the site or subsite you want to delete.
Click Settings. …
Click Delete this site under the Site Actions heading on the Site Settings page. …
On the Delete This Site page, verify that you are deleting the correct site, and then click Delete.
connect 4

Yes, Can be deleted.

Settings>>Delete>>Ok option