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.
Medical Definition of hormonal. 1  1: of, relating to, utilizing, or produced by hormones hormonal changes hormonal disorders hormonal contraceptive methods. 2  2: markedly influenced or affected by hormones (as sex hormones) : exhibiting behavior characteristic of increasing or fluctuating hormone levels hormonal teenagers.