cloud grass vs bent grass

cloud grass and bent grass both are nouns.

Word	Noun	Adjective	Verb	Adverb
cloud grass	Yes	No	No	No
bent grass	Yes	No	No	No

As nouns, bent grass is a hypernym of cloud grass; that is, bent grass is a word with a broader meaning than cloud grass:

cloud grass: Spanish grass with light feathery panicles grown for dried bouquets
bent grass: grass for pastures and lawns especially bowling and putting greens

Other hypernyms of cloud grass include bent-grass, bent.

cloud grass (noun)	bent grass (noun)
Spanish grass with light feathery panicles grown for dried bouquets	grass for pastures and lawns especially bowling and putting greens