(1) /cor·ti·cos·ter·one/ (kor?ti-kos´ter-on) a natural corticoid with moderate glucocorticoid activity, some mineralocorticoid activity, and actions similar to cortisol except that it is not antiinflammatory.
(2) n an adrenal corticosteroid hormone necessary for the maintenance of life in adrenalectomized animals; protects against stress, influences muscular efficiency, and influences carbohydrate and electrolyte metabolism.