You can remove tags for any user, or completely. For this you will need to access each user with the tag and manually remove the tag from their contact:

Once all tags have been removed it will no longer appear in your list of tags.

+1 for tag editing functionality. Deleting tags, editing tag names, adding/deleting tags for multiple contacts.

General tag editing functionality including some way to view/edit the entire list. I want to delete the CEO and San Antonio tags.