egg yolk vs ingredient

egg yolk and ingredient both are nouns.

Word	Noun	Adjective	Verb	Adverb
egg yolk	Yes	No	No	No
ingredient	Yes	No	No	No

As nouns, ingredient is a hypernym of egg yolk; that is, ingredient is a word with a broader meaning than egg yolk:

egg yolk: the yellow spherical part of an egg that is surrounded by the albumen
ingredient: food that is a component of a mixture in cooking

Other hypernyms of egg yolk include fixings.

egg yolk (noun)	ingredient (noun)
the yellow spherical part of an egg that is surrounded by the albumen	a component of a mixture or compound
	an abstract part of something
	food that is a component of a mixture in cooking