plural cloacae
klō-ˈā-ˌkē 
-ˌsē
-ˌsē
1
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
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
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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
Cite this Entry
“Cloaca.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cloaca. Accessed 3 Jul. 2025.
Copy CitationMedical 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
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