- Embryology. the outermost of the extraembryonic membranes of land vertebrates, contributing to the formation of the placenta in the placental mammals.
- Zoology. the membrane around the eggs of certain insects, secreted by cells of the ovary.
Origin of chorion
1535–45; < New Latin < Greek chórion membrane enclosing the fetus
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the outer of two membranes that form a sac around the embryonic reptile, bird, or mammal: contributes to the placenta in mammalsSee also amnion
Word Origin for chorion
C16: from Greek khorion afterbirth
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
"outer membrane of the fetus," 1540s, medical Latin, from Greek khorion "membrane enclosing the fetus, afterbirth," perhaps from PIE *ghere- "gut, entrail" (see yarn).
Online Etymology Dictionary, © 2010 Douglas Harper
- The outer membrane enclosing the embryo in reptiles, birds, and mammals. In placental mammals it contributes to the development of the placenta.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- The outer membrane that encloses the embryo of a reptile, bird, or mammal. In mammals, the chorion contributes to the development of the placenta.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.