Yolk
Yolk (yōlk or yōk; 277) , noun
[Old English yolke, yelke, yolke, yelke, Anglo-Saxon geoloca, geoleca, from geolu yellow. See Yellow.]
1.
The yellow part of an egg; the vitellus.
2.
(Zoology) An oily secretion which naturally covers the wool of sheep.
Collocations (3)
Yolk cord (Zoology) , a slender cord or duct which connects the yolk glands with the egg chambers in certain insects, as in the aphids.
Yolk gland (Zoology) , a special organ which secretes the yolk of the eggs in many turbellarians, and in some other invertebrates. See Illust. of Hermaphrodite in Appendix.
Yolk sack (Anatomy) , the umbilical vesicle. See under Unbilical.