cotyledon

noun

Etymology: From Latin cotylēdōn, from Ancient Greek κοτυληδών (kotulēdṓn, “cup-shaped cavity”), from κοτύλη (kotúlē, “cup”).

1. Each of the patches of villi on the foetal chorion in the placenta of ruminants and some other mammals.

   “Forced to apply animal findings to humans, his human womb also had cotyledons like a dog's.”

2. The leaf of the embryo of a seed-bearing plant; after germination it becomes the first leaves of the seedling.