red dwarf vs flare star

red dwarf and flare star both are nouns.

Word	Noun	Adjective	Verb	Adverb
red dwarf	Yes	No	No	No
flare star	Yes	No	No	No

As nouns, flare star is a hyponym of red dwarf; that is, flare star is a word with a more specific, narrower meaning than red dwarf:

red dwarf: a small, old, relatively cool star; approximately 100 times the mass of Jupiter
flare star: a red dwarf star in which luminosity can change several magnitudes in a few minutes

red dwarf (noun)	flare star (noun)
a small, old, relatively cool star; approximately 100 times the mass of Jupiter	a red dwarf star in which luminosity can change several magnitudes in a few minutes