kaoliang vs grain sorghum

kaoliang and grain sorghum both are nouns.

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

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

kaoliang: sorghums of China and Manchuria having small white or brown grains (used for food) and dry pithy stalks (used for fodder, fuel and thatching)
grain sorghum: any of several sorghums cultivated primarily for grain

kaoliang (noun)	grain sorghum (noun)
sorghums of China and Manchuria having small white or brown grains (used for food) and dry pithy stalks (used for fodder, fuel and thatching)	any of several sorghums cultivated primarily for grain