alcohol vs glycerol

alcohol and glycerol both are nouns.

Word	Noun	Adjective	Verb	Adverb
alcohol	Yes	No	No	No
glycerol	Yes	No	No	No

As nouns, glycerol is a hyponym of alcohol; that is, glycerol is a word with a more specific, narrower meaning than alcohol:

alcohol: any of a series of volatile hydroxyl compounds that are made from hydrocarbons by distillation
glycerol: a sweet syrupy trihydroxy alcohol obtained by saponification of fats and oils

alcohol (noun)	glycerol (noun)
a liquor or brew containing alcohol as the active agent	a sweet syrupy trihydroxy alcohol obtained by saponification of fats and oils
any of a series of volatile hydroxyl compounds that are made from hydrocarbons by distillation