The term "bathyal" is often used to describe depths of the ocean between 200 and 2,000 meters. However, there are several synonyms that can be used interchangeably with the word "bathyal". These synonyms include "abyssal", "demersal", "mesopelagic", and "upper abyssal". "Abyssal" refers to depths greater than 2,000 meters, while "demersal" refers to the ocean floor and its associated organisms. "Mesopelagic" refers to the zone between the surface and bathyal zone, while "upper abyssal" may refer to depths just beyond the bathyal zone. Use of these synonyms can help to add variety and specificity to scientific and technical writing about ocean depths.