an isolated mass, or one of several such masses, of thyroid tissue, sometimes present in the side of the neck, or just above the hyoid bone (suprahyoid accessory thyroid gland), or even as low as the arch of the aorta. Syn: glandula thyroidea accessoria [NA], accessory thyroid, prehyoid gland, suprahyoid gland, thyroidea accessoria, thyroidea ima, Wölfler’s gland.