ergosterol vs sterol

ergosterol and sterol both are nouns.

Word	Noun	Adjective	Verb	Adverb
ergosterol	Yes	No	No	No
sterol	Yes	No	No	No

As nouns, sterol is a hypernym of ergosterol; that is, sterol is a word with a broader meaning than ergosterol:

ergosterol: a plant sterol that is converted into vitamin D by ultraviolet radiation
sterol: any of a group of natural steroid alcohols derived from plants or animals; they are waxy insoluble substances

Other hypernyms of ergosterol include steroid alcohol.

ergosterol (noun)	sterol (noun)
a plant sterol that is converted into vitamin D by ultraviolet radiation	any of a group of natural steroid alcohols derived from plants or animals; they are waxy insoluble substances