cloaca

noun

clo·​a·​ca klō-ˈā-kə 

plural cloacae klō-ˈā-ˌkē  -ˌsē 

1

: sewer entry 3

2

a

[New Latin, from Latin] : the common chamber into which the intestinal and urogenital tracts discharge especially in monotreme mammals, birds, reptiles, amphibians, and elasmobranch fishes

also : a comparable chamber of an invertebrate

b

: the enlarged terminal part of the posterior embryonic digestive tract of a mammal that gives rise to the rectum, upper anal canal, and urogenital sinus

3

: cesspool sense 2

cloacal

klō-ˈā-kəl 

adjective

Examples of cloaca in a Sentence

Recent Examples on the Web

Instead, the males will just press their cloaca directly onto that of females, like the way that birds procreate. —Joshua Rapp Learn, Discover Magazine, 22 July 2024

The milk didn’t come through a nipple, the researchers found, but from within the amphibian’s cloaca in a case of convergent evolution. —Riley Black, Smithsonian Magazine, 13 May 2024

After a gestational period, the female lays those eggs from that selfsame cloaca. —Stephen C. George, Discover Magazine, 16 Apr. 2023

And that a one-stop shop is called a cloaca. —Christie Wilcox, Discover Magazine, 23 Nov. 2017

In female turkeys, the droppings exit the large intestine into the cloaca. —Christie Wilcox, Discover Magazine, 23 Nov. 2017

Sometimes, males will present their cloaca—the single opening for the bird’s digestive, urinary and reproductive tracts—which females inspect, perhaps looking for signs of infection, writes New Scientist’s Christa Lesté-Lasserre. —Margaret Osborne, Smithsonian Magazine, 29 Nov. 2022

In others, muscles surrounding the cloaca could block an unwanted male, or dilate to allow entry to a preferred suitor. —Rachel E. Gross, Smithsonian Magazine, 31 Mar. 2022

Paleontologists have also found on the same Psittacosaurus fossil a dinosaur cloaca and countershading camouflage, Gizmodo reports. —Elizabeth Gamillo, Smithsonian Magazine, 13 June 2022

Word History

Etymology

Latin; akin to Greek klyzein to wash — more at clyster

First Known Use

circa 1656, in the meaning defined at sense 1

Kids Definition

cloaca

noun

clo·​aca

klō-ˈā-kə

plural cloacae

-ˌkē,

-ˌsē

: a chamber into which the intestinal, urinary, and reproductive canals empty in birds, reptiles, amphibians, and some fishes

also : a chamber like this in an invertebrate animal that serves the same purpose

cloacal

-ˈā-kəl

adjective

Medical Definition

cloaca

noun

clo·​aca klō-ˈā-kə 

plural cloacae -ˌkē, -ˌsē 

1

a

: the common chamber into which the intestinal, urinary, and generative canals discharge especially in monotreme mammals, birds, reptiles, amphibians, and elasmobranch fishes

b

: the terminal part of the embryonic hindgut of a mammal before it divides into rectum, bladder, and genital precursors

2

: a passage in a bone leading to a cavity containing a sequestrum

cloacal

-ˈā-kəl 

adjective