That must be a term of art that is particular to the state of Tennessee.  Clarification may only come from asking someone in your area.  As for "disposed," that is a fairly general term used in legal proceedings everywhere.  "Disposed" is the legal end to a case or judicial proceeding.  It is done; over with.  The charges are dismissed for whatever reason ("held to state" may be the clue to this part). It sounds like it is a good thing for you.  I would, however, call the court clerk and double check what happened just to be sure.  You do not want to come to find out later that it was not what we all thought it was.  Good luck.