egg yolk

yellow and principal substance of an egg

The part of a garment, as well as various pieces of equipment, are correctly spelled yoke.An egg yolk is the part of an egg which serves as the food source for the developing embryo inside. Prior to fertilization the yolk together with the germinal disc is a single cell. Mammalian embryos live off their yolk until they implant on the wall of the uterus. The egg yolk is suspended in the egg white (known more formally as albumen or ovalbumin) by one or two spiral bands of tissue called the chalazae.
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Noun
1. the yellow spherical part of an egg that is surrounded by the albumen
(hypernym) ingredient, fixings
(part-holonym) egg, eggs