cloaca

n. sewer; cavity which holds excrement (Zoology)

For other meanings, see Cloaca (disambiguation) In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, urinary, and (usually) genital tracts of certain animal species. The word comes from Latin, and means "sewer". All birds, reptiles, and amphibians possess this orifice, from which they excrete both urine and feces, unlike placental mammals, which possess two separate orifices for evacuation. Marsupials and monotremes also possess one (in marsupials and a few birds, the genital tract is separate). In contrast, each individual among most species of placental mammals and bony fishes has, in lieu of a cloaca, a specialized opening for at least one of these tracts.
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Cloaca /clo·a·ca/ pl. cloa´cae [L.] 1. a common passage for fecal, urinary, and reproductive discharge in most lower vertebrates. 2. [more]Cloaca - Community and Resources

Noun
1. a waste pipe that carries away sewage or surface water
(synonym) sewer, sewerage
(hypernym) drain, drainpipe, waste pipe
(part-holonym) sewage system, sewer system, sewage works

n. cloaca, sewer; cavity which holds excrement (Zoology)