Freebase(0.00 / 0 votes)Rate this definition: Hydroelectricity. Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water.
Definition: Hormones. Hormones. Hormones are chemical substances that act like messenger molecules in the body. After being made in one part of the body, they travel to other parts of the body where they help control how cells and organs do their work. For example, insulin is a hormone that's made by the beta cells in the pancreas.
Hormones are chemicals that carry messages from glands to cells within tissues or organs in the body. They also maintain chemical levels in the bloodstream to help achieve homeostasis, which is a state of stability or balance within the body. There are two types of these chemicals, known as steroids and peptides. The word hormone comes from a Greek word that means to spur on..