wheat vs spelt

wheat and spelt both are nouns.

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

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

wheat: annual or biennial grass having erect flower spikes and light brown grains
spelt: hardy wheat grown mostly in Europe for livestock feed

wheat (noun)	spelt (noun)
a variable yellow tint; dull yellow, often diluted with white	hardy wheat grown mostly in Europe for livestock feed
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