allantois

noun
al·​lan·​to·​is | \ ə-ˈlan-tə-wəs How to pronounce allantois (audio) \
plural allantoides\ ˌa-​lən-​ˈtō-​ə-​ˌdēz How to pronounce allantoides (audio) , ˌa-​ˌlan-​ \

Definition of allantois

: a vascular fetal membrane of reptiles, birds, and mammals that is formed as a pouch from the hindgut and that in placental mammals is intimately associated with the chorion in formation of the placenta

Other Words from allantois

allantoic \ ˌa-​lən-​ˈtō-​ik How to pronounce allantoic (audio) , ˌa-​ˌlan-​ \ adjective

First Known Use of allantois

1615, in the meaning defined above

History and Etymology for allantois

New Latin, ultimately from Greek allant-, allas sausage

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Time Traveler for allantois

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The first known use of allantois was in 1615

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Cite this Entry

“Allantois.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/allantois. Accessed 28 January 2020.

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More Definitions for allantois

allantois

noun
al·​lan·​to·​is | \ ə-ˈlant-ə-wəs How to pronounce allantois (audio) \
plural allantoides\ ˌal-​ən-​ˈtō-​ə-​ˌdēz How to pronounce allantoides (audio) , ˌal-​ˌan-​ How to pronounce allantoides (audio) \

Medical Definition of allantois

: a vascular fetal membrane of reptiles, birds, or mammals that is formed as a pouch from the hindgut and that in placental mammals is intimately associated with the chorion in formation of the placenta

More from Merriam-Webster on allantois

Britannica.com: Encyclopedia article about allantois

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