Relating to or denoting tissues, membranes, or structures that develop outside the embryo but support its growth and development.
From 'extra-' (outside) + 'embryonic' (relating to the embryo). This developmental biology term became standard in 20th-century embryology textbooks.
Your amnion, chorion, and allantois are all 'extraembryonic' membranes—they're absolutely essential to your survival in the womb, but your body doesn't keep them after birth, showing how evolution repurposes structures temporarily.
Complete word intelligence in one call. Free tier — 50 lookups/day.