thy·roid-stim·u·lat·ing hormone 
(thīroid-stĭm′yə-lā′tĭng)
(thīroid-stĭm′yə-lā′tĭng)n. Abbr. TSH
A hormone secreted by the anterior lobe of the pituitary gland that stimulates and regulates the activity of the thyroid gland. Also called thyrotropin.