placenta
noun
pla·cen·ta plə-ˈsen-tə 
plural placentas or placentae plə-ˈsen-(ˌ)tē
1
: the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates its metabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues
also : an analogous organ in another animal
2
: a sporangium-bearing surface
especially : the part of the carpel bearing ovules
Examples of placenta in a Sentence
Recent Examples on the Web
We’re bound together by our great-great-great-great-great (just 60 million more to go) grandmother’s placenta. —
Hannah Towey, Condé Nast Traveler, 22 Apr. 2026 For example, Doppler ultrasounds are used to evaluate blood flow between the placenta and fetus, allowing for the early identification of potential issues. —Memorialcare Saddleback Medical Center, Oc Register, 16 Apr. 2026 The true placenta of the placentals allows for a longer developmental period within the protection of the womb, a factor considered to have contributed to the evolutionary success of the group. —Encyclopedia Britannica, 2 Apr. 2026 They’ve been found in human organs and tissue, such as brains, livers, placentas and testicles. —Susanne Rust follow, Los Angeles Times, 2 Apr. 2026 See All Example Sentences for placenta
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Hannah Towey, Condé Nast Traveler, 22 Apr. 2026 For example, Doppler ultrasounds are used to evaluate blood flow between the placenta and fetus, allowing for the early identification of potential issues. —Memorialcare Saddleback Medical Center, Oc Register, 16 Apr. 2026 The true placenta of the placentals allows for a longer developmental period within the protection of the womb, a factor considered to have contributed to the evolutionary success of the group. —Encyclopedia Britannica, 2 Apr. 2026 They’ve been found in human organs and tissue, such as brains, livers, placentas and testicles. —Susanne Rust follow, Los Angeles Times, 2 Apr. 2026 See All Example Sentences for placenta
Cite this Entry
“Placenta.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.grautoblog.com/dictionary/placenta. Accessed 27 Apr. 2026.
Copy CitationKids Definition
placenta
noun
pla·cen·ta plə-ˈsent-ə
plural placentas or placentae -ˈsent-ē
: the organ in most mammals by which the fetus is joined to the uterus of the mother and is nourished
placental
adjective
-ˈsent-ᵊl
Medical Definition
placenta
noun
pla·cen·ta plə-ˈsent-ə
plural placentas or placentae -ˈsent-(ˌ)ē
: the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates its metabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues permitting exchange of material by diffusion between the maternal and fetal vascular systems but without direct contact between maternal and fetal blood and typically involving the interlocking of fingerlike vascular chorionic villi with corresponding modified areas of the uterine mucosa
see abruptio placentae
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