amnion

[ am-nee-uh n ]
/ ˈæm ni ən /
SEE SYNONYMS FOR amnion ON THESAURUS.COM

noun, plural am·ni·ons, am·ni·a [am-nee-uh] /ˈæm ni ə/.

Anatomy, Zoology. the innermost of the embryonic or fetal membranes of reptiles, birds, and mammals; the sac in which the embryo is suspended.
Zoology. a similar membrane of insects and other invertebrates.

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Origin of amnion

1660–70; < Greek, equivalent to amn(ós) lamb (see yean) + -ion diminutive suffix

Words nearby amnion

amniocentesis, amniochorial, amniogenesis, amniography, amnioma, amnion, amnion nodosum, amnionitis, amniorrhea, amniorrhexis, amnioscope
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Words related to amnion

afterbirth, placenta

Example sentences from the Web for amnion

British Dictionary definitions for amnion

amnion
/ (ˈæmnɪən) /

noun plural -nions or -nia (-nɪə)

the innermost of two membranes enclosing an embryonic reptile, bird, or mammalSee also chorion

Word Origin for amnion

C17: via New Latin from Greek: a little lamb, from amnos a lamb
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

Medical definitions for amnion

amnion
[ ăm′nē-ən, -ŏn′ ]

n. pl. am•ni•ons

The thin, membranous sac filled with a serous fluid in which the embryo or fetus is enclosed and suspended in the uterus.amniotic sac

Other words from amnion

am′ni•ot′ic (-ŏt′ĭk) null adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for amnion

amnion
[ ăm′nē-ən ]

A thin, membranous sac filled with a watery fluid (called the amniotic fluid) in which the embryo or fetus of a reptile, bird, or mammal is suspended during prenatal development. Also called amniotic sac
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.