placenta

noun

pla·cen·ta | \ plə-ˈsen-tə

plural placentas or placentae\ plə-ˈsen-(ˌ)tē

Definition of placenta

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

The clinic told Denver police, who turned over a placenta sample to a Rapid City detective. — USA TODAY, "Emoji house, Saharan dust, turtle crossing: News from around our 50 states," 8 Aug. 2019 One still had a placenta and umbilical cord attached. — Lauren Fox, BostonGlobe.com, "Mother in Blackstone ‘house of horrors’ case sentenced to 6 to 8 years in prison," 11 July 2019 These cells eventually develop into the placenta, the organ that surrounds a developing fetus. — Daniela Hernandez, WSJ, "New Noninvasive Genetic Tests for IVF Embryos Are in Development," 24 June 2019 Somehow, the Zika virus can sneak from the mother’s bloodstream across the placenta, which protects and nourishes the fetus, and target the fetus’ brain. — Washington Post, "Scientists feel chill of crackdown on fetal tissue research," 9 June 2019 Something was wrong with Florio’s placenta, and Connor hadn’t been receiving enough nutrients to grow at a normal rate. — Cathy Free, The Seattle Times, "Baby born last year weighing less than a soda can heads home for the first time," 12 Apr. 2019 One still had a placenta and umbilical cord attached. — Lauren Fox, BostonGlobe.com, "Mother in Blackstone ‘house of horrors’ case sentenced to 6 to 8 years in prison," 11 July 2019 After that, staffers look for the placenta to pass and for nursing behaviors to begin. — Steve Johnson, chicagotribune.com, "Shedd Aquarium beluga gives birth to healthy calf," 4 July 2019 Just as frightening is this: T. cruzi can cross the placenta. — Marc Burckhardt, National Geographic, "A little-known parasite infects 300,000 people in the U.S.," 17 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'placenta.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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Last Updated

13 Aug 2019

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The first known use of placenta was in 1638

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More Definitions for placenta

placenta

noun

English Language Learners Definition of placenta

medical : the organ in mammals that forms inside the mother's uterus, nourishes the unborn baby, and is pushed out of the mother after the birth of the baby

See the full definition for placenta in the English Language Learners Dictionary

placenta

noun

pla·cen·ta | \ plə-ˈsen-tə

Kids Definition of placenta

: the organ in most mammals by which the fetus is joined to the uterus of the mother and is nourished

placenta

noun

pla·cen·ta | \ plə-ˈsent-ə

plural placentas or placentae\ -ˈsent-(ˌ)ē

Medical Definition of placenta

: 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