flour vs rye flour

flour and rye flour both are nouns.

Word	Noun	Adjective	Verb	Adverb
flour	Yes	No	Yes	No
rye flour	Yes	No	No	No

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

flour: fine powdery foodstuff obtained by grinding and sifting the meal of a cereal grain
rye flour: flour made from ground rye grain.

Other hyponyms of flour include plain flour, wheat flour, soy flour, soybean flour, soybean meal, semolina.

flour (noun)	rye flour (noun)
fine powdery foodstuff obtained by grinding and sifting the meal of a cereal grain	flour made from ground rye grain.

flour (verb)	rye flour (verb)
convert grain into flour
cover with flour