brunch vs eat

brunch is a noun but eat is not a noun.

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

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

brunch (noun)	eat (noun)
combination of breakfast and lunch; usually served in late morning

brunch (verb)	eat (verb)
eat a meal in the late morning	cause to deteriorate due to the action of water, air, or an acid
	take in solid food
	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