- The definition of a cotyledon is the first leaf or set of leaves that sprout from a seed.
An example of a cotyledon is the first two leaves that sprout from a sunflower seed.
Origin of cotyledonModern Latin ; from Classical Latin name of a plant ; from Classical Greek kotylēdōn ; from kotylē, a hollow, cavity
- 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.
- Anatomy One of the lobules constituting the uterine side of the mammalian placenta, consisting mainly of a rounded mass of villi.
Origin of cotyledonLatin cotylēdōn, navelwort, from Greek kotulēdōn, from kotulē, hollow object.
- cot′y·le′don·ar′y , cot′y·le′don·al , cot′y·le′do·nous
bean seed germinating
From Latin cotyledon, from Ancient Greek κοτυληδών (kotulēdōn, “cup-shaped cavity”), from κοτύλη (kotulē, “cup”).