ˈyōk also ˈyōlk dial ˈyelk or ˈyəlk noun
or yoke ˈyōk
( -s )
Etymology: Middle English yolke, yelke, from Old English geolca, geoloca, from geolu yellow — more at yellow
1.
a. : the yellow spheroidal mass of stored food that forms the inner portion of the egg of a bird or reptile and is surrounded by the white — see white yolk , yellow yolk ; egg illustration
b. archaic : the whole contents of an ovum which may be distinguished into a protoplasmic formative portion and an ergastric nutritive portion
c. : the material stored in an ovum that supplies food material to the developing embryo, consists chiefly of vitellin, nucleoprotein and other proteins, lecithin, and cholesterol, may be sparse and diffuse (as in a placental mammal) or copious and specifically arranged (as at the center or at one pole of the ovum), and when copious exerts a profound influence on the course of segmentation
2.
[probably alteration of (assumed) Middle English yoke, from (assumed) Old English ēowoca; akin to Middle Dutch ieke yolk (of wool); derivative from the root of English ewe (I) ]
: oily material permeating wool in the natural state and consisting of wool fat, suint, and debris of various sorts
3. obsolete : the best or most important part : center , essence