Cotyledon

[kot-l-eed-n] /ˌkɒt lˈid n/

noun, Botany.
1.
the primary or rudimentary leaf of the embryo of seed plants.
2.
Anatomy. any of several lobules of the placenta.
/ˌkɒtɪˈliːdən/
noun
1.
a simple embryonic leaf in seed-bearing plants, which, in some species, forms the first green leaf after germination
2.
a tuft of villi on the mammalian placenta
n.

from 1540s, in various sense, from Latin cotyledon “pennywort, navelwort,” from Greek kotyledon “cup-shaped cavity,” from kotyle “hollow thing, small vessel,” also the name of a small liquid measure (nearly a half-pint); of uncertain origin. Botanical sense is 1776, from Linnaeus (1751).

cotyledon cot·y·le·don (kŏt’l-ēd’n)
n.

cotyledon
(kŏt’l-ēd’n)
A leaf of the embryo of a seed-bearing plant. Most cotyledons emerge, enlarge, and become green after the seed has germinated. Cotyledons either store food for the growing embryo (as in monocotyledons) or absorb food that has been stored in the endosperm (as in other angiosperms) for eventual distribution to the growing parts of the embryo. Also called seed leaf. See more at eudicotyledon, monocotyledon.