"pertaining to the cavity of the abdomen," 1660s, from Latin coeliacus, from Greek koiliakos "pertaining to the bowels," also "pain in the bowels," from koilia "bowels, abdominal cavity, intestines, tripe" from koilos "hollow," from PIE root *keue- "to swell," also "vault, hole."
co-ed
co-education
co-educational
coefficient
coelacanth
coeliac
coelo-
coelomate
coeno-
coequal
coerce