The use of punctuation in English can change from place to place and from time to time. Modern typography suggests that punctuation should only be used when there is a need. That results in less punctuation than was the case the early 20th century.
Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland. Hormones are essential for every activity of life, including the processes of digestion, metabolism, growth, reproduction, and mood control. Many hormones, such as neurotransmitters, are active in more than one physical process.
LINK / CITE ADD TO WORD LIST. noun. The definition of a hormone is a substance formed in an organ or tissue in the body of a plant or animal and then transported by body fluid to another organ or tissue for a specific action.An example of a hormone is estrogen in humans. substance, usually a peptide or steroid, produced by one tissue and conveyed by the bloodstream to another to effect physiological activity, such as growth or metabolism. b. A synthetic compound that acts like a hormone in the body.