Main Entry: cot·y·le·don

Pronunciation: \ˌkä-tə-ˈlē-d^ən\

Function: noun

Etymology: New Latin, from Greek kotylēdōn cup-shaped hollow, from kotylē cup, anything hollow

Date: 1540

1 : a lobule of the mammalian placenta
2 : the first leaf or one of the first pair or whorl of leaves developed by the embryo of a seed plant or of some lower plants (as ferns)

— cot·y·le·don·ary \-ˈlē-də-ˌner-ē\ adjective