cotyledon

noun

cot·​y·​le·​don ˌkä-tə-ˈlē-dᵊn How to pronounce cotyledon (audio)
plural cotyledons
1
: the first leaf or one of the first pair or whorl of leaves developed by the embryo of a seed plant see seedling illustration
2
: a small lobe of the mammalian placenta that facilitates the delivery of oxygen and nutrients to the fetus
cotyledonary adjective
cotyledonary position

Word History

Etymology

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

First Known Use

1540, in the meaning defined at sense 2

Time Traveler
The first known use of cotyledon was in 1540

Dictionary Entries Near cotyledon

Cite this Entry

“Cotyledon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cotyledon. Accessed 14 Nov. 2024.

Kids Definition

cotyledon

noun
cot·​y·​le·​don ˌkät-ᵊl-ˈēd-ᵊn How to pronounce cotyledon (audio)
: the first leaf or one of the first leaves developed by the embryo of a seed plant that is usually folded within the seed until germination and serves as a storehouse of food

called also seed leaf

Medical Definition

cotyledon

noun
cot·​y·​le·​don ˌkät-ᵊl-ˈēd-ᵊn How to pronounce cotyledon (audio)
1
: a lobule (see lobule sense 2) of a mammalian placenta that facilitates the delivery of oxygen and nutrients to the fetus
2
: the first leaf or one of the first pair or whorl of leaves developed by the embryo of a seed plant
cotyledonary adjective

More from Merriam-Webster on cotyledon

Last Updated: - Definition revised
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