beetroot vs sugar beet

beetroot and sugar beet both are nouns.

Word	Noun	Adjective	Verb	Adverb
beetroot	Yes	No	No	No
sugar beet	Yes	No	No	No

As nouns, sugar beet is a hyponym of beetroot; that is, sugar beet is a word with a more specific, narrower meaning than beetroot:

Other hyponyms of beetroot include mangel-wurzel.

beetroot (noun)	sugar beet (noun)
round red root vegetable	white-rooted beet grown as a source of sugar
beet having a massively swollen red root; widely grown for human consumption	form of the common beet having a sweet white root from which sugar is obtained