1. Having no enclosing or confining barrier.
  2. Being in a position or adjustment to permit passage. Not shut or locked.
  3. Completely free from concealment. Exposed to general view or knowledge.
  4. Exposed or vulnerable to attack or question.
  5. Having no protective covering.
  6. Having the skin cracked, cut, or broken so that underlying tissue is exposed.
  7. Not restricted to a particular group or category of participants.
  8. Presenting no obstacle to passage or view.
  9. Available to follow or make use of. Not taken up with duties or engagements.
  10. Not finally decided. Subject to further consideration.
  11. Characterized by ready accessibility and usually generous attitude.

The emotion of Openness is found in the Lung meridian in the Metal element.

Definition from Dictionary by Merriam-Webster.