amnion

American  

[am-nee-uhn] / ˈæm ni ən /

noun

amnions, plural amnia plural

1. Anatomy, Zoology. the innermost of the embryonic or fetal membranes of reptiles, birds, and mammals; the sac in which the embryo is suspended.

2. Zoology. a similar membrane of insects and other invertebrates.

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amnion British  

/ ˈæmnɪən /

noun

1. the innermost of two membranes enclosing an embryonic reptile, bird, or mammal See also chorion

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amnion Scientific  

/ ăm′nē-ən /

1. 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.

2. Also called amniotic sac

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Other Word Forms

Inflected Forms

noun

• amnions
  plural
• amnia
  plural

Etymology

Origin of amnion

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