Definition - What does Ex Officio mean?
Ex officio is a Latin term that means "from the office." It is used to refer to an individual who gets membership to a body (council, commission, council, etc.,) by the virtue of him or her holding another office instead of being appointed or elected.
Justipedia explains Ex Officio
Some people wrongly believe that the rights of an ex officio member within a body are limited by their status; while that may be true in certain cases, the meaning of the term ex officio is limited to how one becomes member of a body and does not directly impact the rights of that person. Unless the rules governing the body restrict the rights of an ex officio member, he or she enjoys the same rights as any member who has been appointed or elected to the body.