Monimolimnion is a term used to describe the deepest, coldest, least-oxygenated layer of a stratified lake or reservoir. There are several synonyms for this word that are commonly used in scientific literature. These include the hypolimnion, which refers to the lowermost layer of water in a lake or reservoir, the deepwater layer, and the bottom layer. Some other synonyms for monimolimnion include the benthic layer, the abyssal layer, and the profundal layer. Regardless of the terminology used, the monimolimnion is an important component of freshwater ecosystems, and its study can provide valuable insights in terms of water quality, nutrient cycling, and biodiversity.