from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Botany A leaf of the embryo of a seed plant, which upon germination either remains in the seed or emerges, enlarges, and becomes green. Also called seed leaf.
- n. Anatomy One of the lobules constituting the uterine side of the mammalian placenta, consisting mainly of a rounded mass of villi.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The leaf of the embryo of a seed-bearing plant; after germination it becomes the first leaves of the seedling.
Latin cotylēdōn, navelwort, from Greek kotulēdōn, from kotulē, hollow object.(American Heritage® Dictionary of the English Language, Fourth Edition)