Cœlomate is a term used in biology to refer to organisms that have a true coelom, which is a fluid-filled cavity that separates the body wall from the gut. Some synonyms for cœlomate include coelomic, Eucoelomate, and schizocoelous. Alternatively, the absence of a true coelom is referred to as acoelomate or pseudocoelomate. Acoelomate means 'no cavity,' referring to organisms that have no body cavity between the gut and body wall, while pseudocoelomate means 'false cavity,' which describes organisms with a fluid-filled cavity that is distinct from the true coelom found in coelomates. Understanding these terms can help biologists describe and classify organisms based on their body cavity structure.