wheat vs cracked wheat

wheat and cracked wheat both are nouns.

Word	Noun	Adjective	Verb	Adverb
wheat	Yes	No	No	No
cracked wheat	Yes	No	No	No

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

wheat: grains of common wheat; sometimes cooked whole or cracked as cereal; usually ground into flour
cracked wheat: grains of wheat that have been crushed into small pieces

Other hyponyms of wheat include bulghur, bulgur, bulgur wheat.

wheat (noun)	cracked wheat (noun)
a variable yellow tint; dull yellow, often diluted with white	grains of wheat that have been crushed into small pieces
grains of common wheat; sometimes cooked whole or cracked as cereal; usually ground into flour
annual or biennial grass having erect flower spikes and light brown grains