名詞 cotyledon:

1. embryonic leaf in seed-bearing plants
   同義詞：seed leaf

1. Two cotyledons have come out from the seedling.
   小苗長出了兩片子葉。

cot.y.le.don

n.（名詞）
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
【植物學】 子葉：種子植物胚的葉片，在萌芽過程中，它或者保持在種子里或者出來，變大并變綠也作 seed leaf
Anatomy One of the lobules constituting the uterine side of the mammalian placenta, consisting mainly of a rounded mass of villi.
【解剖學】 絨毛葉：組成哺乳動物胎盤的子宮邊的小葉之一，主要由團裝絨毛組成

來源：
Latin [navelwort]
拉丁語 [臍景天]
from Greek kotulôdôn
源自 希臘語 kotulôdôn
from kotulô [hollow object]
源自 kotulô [空心物體]

【引伸】
cot.yle.donal 或
cot.yle.donous