Abyssopelagic refers to the deep oceanic zone that extends from a depth of 4,000 meters to the ocean floor. Synonyms for abyssopelagic include the midnight zone, the bathypelagic zone, and the abyssal zone. Additionally, the term hadal zone refers to the even deeper oceanic trenches, which reach depths of over 6,000 meters. These zones are characterized by extreme pressure, temperatures, and darkness, yet they are home to a variety of unique and unusual creatures adapted to life in these extreme conditions. Synonyms for abyssopelagic and its related zones are often used interchangeably in discussions of deep sea ecology and exploration.