nibble vs eat

nibble is a noun but eat is not a noun.

Word	Noun	Adjective	Verb	Adverb
nibble	Yes	No	Yes	No
eat	No	No	Yes	No

As verbs, eat is a hypernym of nibble; that is, eat is a word with a broader meaning than nibble:

nibble (noun)	eat (noun)
gentle biting
a small byte

nibble (verb)	eat (verb)
eat intermittently; take small bites of	cause to deteriorate due to the action of water, air, or an acid
bite off very small pieces	take in solid food
bite gently	eat a meal; take a meal
	take in food; used of animals only
	use up (resources or materials)
	worry or cause anxiety in a persistent way