growth hormone

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A polypeptide hormone secreted by the anterior lobe of the pituitary gland that promotes growth of the body, especially by stimulating release of somatomedin, and that influences the metabolism of proteins, carbohydrates, and lipids.
• noun Any of various natural or synthetic substances that regulate the growth of animals or plants, such as auxins in plants.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any polypeptide hormone, secreted by the pituitary gland, that promotes growth and regulates the metabolism of carbohydrates, proteins and lipids.
• noun Any synthetic substance that promotes growth in animals or plants.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a hormone produced by the anterior pituitary gland; promotes growth in humans