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

From snail mucin to placenta, skincare seems to experience one fad after another. —Tanya Benedicto Klich, Forbes, 3 Dec. 2024

Plastic has even been found in human placentas, breast milk and the stools of newborn babies — in other words, our children are being born pre-polluted. —Michael Shank, Baltimore Sun, 1 Nov. 2024

Studies also show forever chemicals can transfer to children through the placenta or breastfeeding. —Ignacio Calderon, USA TODAY, 8 Nov. 2024

Newborns are given vitamin K after birth since the transport of vitamin K through the placenta is poor. —Allison Herries, Verywell Health, 7 Oct. 2024

Word History

Etymology

New Latin, from Latin, flat cake, from Greek plakoenta, accusative of plakoeis, from plak-, plax flat surface — more at fluke entry 2

First Known Use

1638, in the meaning defined at sense 1

Kids 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

-ˈsent-ᵊl

adjective

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