al·lan·to·is
| \ ə-ˈlan-tə-wəs
\
\
plural allantoides\
ˌa-lən-ˈtō-ə-ˌdēz
, ˌa-ˌlan-
\
, 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
, ˌa-ˌlan-
\
adjective
, ˌa-ˌlan-
\
adjective
Learn More About allantois
Statistics for allantois
Look-up Popularity
Cite this Entry
“Allantois.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/allantois. Accessed 21 May. 2022.
Style: MLA
MLA
Chicago
APA
Merriam-Webster
Chicago
APA
Merriam-Webster
More Definitions for allantois
allantois
noun
al·lan·to·is
| \ ə-ˈlant-ə-wəs
\
\
plural allantoides\
ˌal-ən-ˈtō-ə-ˌdēz
, ˌal-ˌan-
\
, ˌal-ˌan-
\
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
Test Your Vocabulary
Which Word Does Not Belong?
-
- Which of these words does not mean "nonsense"?
Test your visual vocabulary with our 10-question challenge!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Words at Play
-
You're (Probably) Saying It Wrong
18 words even you might be mispronouncing
-
Great Big List of Beautiful & Useless Words
Along with their degrees of usefulness
-
12 French Phrases from Downton Abbey
Many of us have an 'idée fixe'
-
Words For Things You Didn't Know Have Names
When 'thingamajig' and 'thingamabob' just won't do
Ask the Editors
Word Games
-
The Great British Vocabulary Quiz
Make sure you know the difference between a loo a...
Take the quiz
-
Face Your Fears
Don't be scared to answer these questions about f...
Take the quiz
-
Yearbook Superlatives Quiz
"Most Likely to Use Obscure Words"
Take the quiz
-
Lexigo
Find the hidden words by solving the clues
Take the quiz
Share allantois
Time Traveler for allantois
The first known use of allantois was in 1615
See more words from the same year