crumb cake vs cake

crumb cake and cake both are nouns.

Word	Noun	Adjective	Verb	Adverb
crumb cake	Yes	No	No	No
cake	Yes	No	Yes	No

As nouns, cake is a hypernym of crumb cake; that is, cake is a word with a broader meaning than crumb cake:

crumb cake: cake or coffeecake topped with a mixture of sugar and butter and flour
cake: baked goods made from or based on a mixture of flour, sugar, eggs, and fat

crumb cake (noun)	cake (noun)
cake or coffeecake topped with a mixture of sugar and butter and flour	a block of solid substance (such as soap or wax)
	baked goods made from or based on a mixture of flour, sugar, eggs, and fat
	small flat mass of chopped or ground food

crumb cake (verb)	cake (verb)
	form a coat over