A thyroid protein that is the precursor to iodine-containing hormones and is typically present in the colloid of thyroid gland follicles.
A substance extracted from the thyroid glands of hogs, formerly used as a thyroid hormone supplement to treat hypothyroidism.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.