- Pertaining to the amnion.
Variant of amnion
nounpl. amnions or amnia
- the innermost membrane of the sac enclosing the embryo of a mammal, reptile, or bird: it is filled with a watery fluid ()
- a similar membrane of certain invertebrates, esp. insects
Origin of amnionClassical Greek diminutive of amnos, lamb ; from Indo-European an unverified form agwhnos from source yean, Classical Latin agnus