Yolk

Chamber's Twientieth Century Dictionary · 1908 · p. 125

yōk, Yelk , yelk, n. the yellow part of an egg: the vitellus of a seed: wool-oil.— adjs. Yolked , having a yolk; Yolk′y , like yolk. [A.S. geoloca , geoleca — geolo , yellow.]