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YOB
yob
yobbo
yocto-
yod
yodel
yodh
yodle
yoga
Yogalates
yogh
yoghurt
yogi
yogic
yogurt
Yogyakarta
Yoho National Park
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yolk sac
yolk sac (plural yolk sacs)


noun 
Definition:
 
membrane surrounding embryo: a thin membrane surrounding the embryo in birds, fish, reptiles, and mammals. In birds, fish, and reptiles, it encloses the yolk.
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