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placentation

American  
[plas-uhn-tey-shuhn] / ˌplæs ənˈteɪ ʃən /

noun

  1. Anatomy, Zoology.

    1. the formation of a placenta.

    2. the manner of placement or construction of a placenta.

  2. Botany. the disposition or arrangement of a placenta or placentas.


placentation British  
/ ˌplæsɛnˈteɪʃən /

noun

  1. botany the way in which ovules are attached in the ovary

  2. zoology

    1. the way in which the placenta is attached in the uterus

    2. the process of formation of the placenta

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of placentation

From French, dating back to 1750–60; see origin at placenta, -ation

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Progesterone secreted by the corpus luteum stimulates the production of decidual cells of the endometrium that nourish the blastocyst before placentation.

From Textbooks • Jun. 19, 2013

The placenta develops throughout the embryonic period and during the first several weeks of the fetal period; placentation is complete by weeks 14–16.

From Textbooks • Jun. 19, 2013

An artificial womb has been created for a relative of the grey nurse shark, but sharks’ placentation and how they grow in the womb is a bit less complicated than in humans.

From Salon • Sep. 19, 2012

In some flowers of Rhododendron I have observed a similar condition of the ovules, which, moreover, in the primary flowers, were attached to the walls of the carpels—parietal placentation.

From Vegetable Teratology An Account of the Principal Deviations from the Usual Construction of Plants by Masters, Maxwell T.

But the remarkable discoveries published by the distinguished zoologist Selenka in 1890 proved that man shares these peculiarities of placentation with the anthropoid apes, though they are not found in the other apes.

From The Evolution of Man — Volume 1 by Haeckel, Ernst Heinrich Philipp August