coelom

coe·lom also ce·lom or coe·lome   (sē'ləm)    n.  The cavity within the body of all animals higher than the coelenterates and certain primitive worms, formed by the splitting of the embryonic mesoderm into two layers. In mammals it forms the peritoneal, pleural, and pericardial cavities. Also called body cavity. [German Koelom, from Greek koilōma, cavity, from koilos, hollow; see keuə- in Indo-European roots.] coe·lom'ic (sĭ-lŏm'ĭk, -lō'mĭk) adj.

Main Entry: coe·lom
Pronunciation: 'sE-l&m
Function: noun
Inflected Form: plural coeloms or coe·lo·ma·ta /si-'lO-m&t-&/
: the usually epithelium-lined body cavity of metazoans above the lower worms that forms a large space when welldeveloped between the digestive tract and the body wall —coe·lo·mate /'sE-l&-"mAt/ adjective or noun —coe·lo·mic /si-'läm-ik, -'lO-mik/ adjective

coelom coe·lom or ce·lom or coe·lome (sē'ləm)
n.
The cavity formed by the splitting of the embryonic mesoderm into two layers; in mammals it then forms into the peritoneal, pleural, and pericardial cavities.

coelom   (sē'ləm)  Pronunciation Key  The body cavity that forms from the mesoderm during the embryonic development of more complex animals. The coelom suspends the gut in fluid in the middle of the body, protecting it from gravity and allowing great increases in body size. The presence or absence of a coelom is important for the classification of animal phyla. See more at deuterostome, protostome.