egg yolk

noun

yellow, embryo-containing part of a bird egg

Wiktionary

noun

Etymology: From Middle English egyolk, egge yolk, equivalent to egg + yolk. Compare Dutch eigeel (“egg yolk”), German Low German Eigeel (“egg yolk”), German Eigelb (“egg yolk”), Swedish äggula (“egg yolk”).

The central part of a chicken’s (or other bird’s) egg, yellow when fresh.