Chemolithotrophic refers to an organism that can derive energy from inorganic compounds through chemosynthesis. Some synonyms for chemolithotrophic are lithotrophic, chemoautotrophic, and chemosynthetic. Lithotrophic is derived from the Greek word "lithos" meaning stone and "trophic" meaning nourishing. Chemoautotrophic signifies the use of chemical substances and autotrophic refers to organisms that produce their own food. Chemolithotrophic and chemosynthetic both denote the use of inorganic substances in energy production. These terms are often used interchangeably to describe microorganisms that thrive in extreme environments such as deep sea hydrothermal vents, volcanic vents, and geysers.