cretinism Underactivity of the thyroid gland (hypothyroidism) in children, resulting in poor growth, severe mental retardation and deafness. Commonly the result of a dietary deficiency of iodine; may be congenital if the mother's iodine intake was severely inadequate during pregnancy. Hypothyroidism in adults is myxoedema.

cretinism The condition that results from inadequate secretion of thyroid hormones during fetal life or early infancy. The brain and skeleton fail to develop properly, resulting in mental retardation and dwarfism.

cretinism (kret-in-izm) n. a syndrome of dwarfism, mental retardation, and coarseness of the skin and facial features due to congenital hypothyroidism.