Final answer:
Cushing's disease is a disorder characterized by the hypersecretion of glucocorticoids, specifically cortisol, caused by a pituitary tumor that secretes excessive amounts of ACTH.
Step-by-step explanation:
Cushing's disease is a disorder characterized by the hypersecretion of glucocorticoids, specifically cortisol, which is a type of steroid hormone. The most common cause of Cushing's disease is a pituitary tumor that secretes excessive amounts of adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal glands to produce excessive cortisol.