Addison's disease \Ad"di*son's dis*ease"\ [Named from Thomas Addison, M. D., of London, who first described it.] (Med.) A morbid condition causing a peculiar brownish discoloration of the skin, hypotension, and loss of weight; it is due to insufficient secretion of adrenocortical hormones. Untreated disease is usually fatal. Called also {chronic adrenocortical insufficiency} [1913 Webster + AS]