The following words and phrases, whenever used in ORS 127.800 to 127.897, have the following meanings: (1) "Adult" means an individual who is 18 years of age or older. (2) "Attending physician" means the physician who has primary responsibility for the care of the patient and treatment of the patient's terminal disease. (3) "Capable" means that in the opinion of a court or in the opinion of the patient's attending physician or consulting physician, psychiatrist or psychologist, a patient has the