When a company says that the essential oils they are selling are
  'therapeutic grade', what kind of real meaning can be attached to that?

They are either misinformed .. or informed but chose to fib in order to sell
more oils.    It is Marketing Hype.  But .. it works to sell products to the
uninformed.  Likewise, Medicinal Grade works .. but it too is Marketing
Hype.

  Read more at http://lavenderessentialoils.com