Definition of "extra-embryonic" [extra-embryonic]

• Not forming a part of the embryo proper; specifically, noting that portion of the vertebrate embryo which lies outside of the umbilical stalk.

The Century Dictionary (Public Domain)

• "A trophectoderm is: The extra-embryonic part of the ectoderm of mammalian embryos at the blastocyst stage before the mesoderm becomes associated with the ectoderm."
• "The finding that these extra-embryonic transplants elicited the same effects as the intraembryonic grafts gave definite evidence for the diffusible nature of tumoral nerve growth promoting factor."
• "The space between the amnion and the serosa constitutes the extra-embryonic celom, and for a time communicates with the embryonic celom."