milo vs grain sorghum

milo and grain sorghum both are nouns.

Word	Noun	Adjective	Verb	Adverb
milo	Yes	No	No	No
grain sorghum	Yes	No	No	No

As nouns, grain sorghum is a hypernym of milo; that is, grain sorghum is a word with a broader meaning than milo:

milo: small drought-resistant sorghums having large yellow or whitish grains
grain sorghum: any of several sorghums cultivated primarily for grain

milo (noun)	grain sorghum (noun)
small drought-resistant sorghums having large yellow or whitish grains	any of several sorghums cultivated primarily for grain