Medical Dictionary

cotyledon

noun cot·y·le·don \ˌkät-əl-ˈēd-ən\

Medical Definition of COTYLEDON

1
:  a lobule of a 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 \-ˈēd-ən-ˌer-ē\ adjective

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