A mercury-vapor lamp is a type of gas discharge lamp that emits a blue-green light. It is commonly used in street lighting, as well as in commercial and industrial applications. There are several synonyms for mercury-vapor lamps, including mercury lamps, low-pressure mercury lamps, high-pressure mercury lamps, and fluorescent lamps. These lamps are characterized by their high efficiency and low operating costs, making them an ideal choice for outdoor and indoor lighting applications. However, due to their high mercury content, they require proper disposal to prevent environmental contamination. Despite this, the use of mercury-vapor lamps remains widespread due to their reliability and efficiency.