cloaca

Concise Oxford English Dictionary © 2008 Oxford University Press:
cloaca /kləʊˈeɪkə/

▶noun (pl. cloacae /-siː, -kiː/)

• 1 Zoology a common cavity at the end of the digestive tract for the release of both excretory and genital products in vertebrates (except most mammals) and certain invertebrates.

• 2 archaic a sewer.

– derivatives
cloacal adjective.

– origin C16: from L., rel. to cluere ‘cleanse’.