Search the dictionary A Chinese word or character, or English Draw a character Search 2 entries. luǎnhuángnáng 卵黄囊 yolk sac (ectodermal cells attaching fetus to uterus before the development of the placenta) luǎnhuángnáng 卵黃囊 yolk sac (ectodermal cells attaching fetus to uterus before the development of the placenta)