meal vs brunch

meal and brunch both are nouns.

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

As nouns, brunch is a hyponym of meal; that is, brunch is a word with a more specific, narrower meaning than meal:

meal (noun)	brunch (noun)
the food served and eaten at one time	combination of breakfast and lunch; usually served in late morning
coarsely ground foodstuff; especially seeds of various cereal grasses or pulse
any of the occasions for eating food that occur by custom or habit at more or less fixed times

meal (verb)	brunch (verb)
	eat a meal in the late morning