myxedema myx·e·de·ma (mĭk'sĭ-dē'mə) n. A disease caused by decreased activity of the thyroid gland in adults and characterized by dry skin, swellings around the lips and nose, mental deterioration, and a subnormal basal metabolic rate.
myx'e·dem'a·tous (-děm'ə-təs, -dē'mə-) or myx'e·dem'ic (-děm'ĭk) adj.