alizarin crimson vs alizarin

alizarin crimson and alizarin both are nouns.

Word	Noun	Adjective	Verb	Adverb
alizarin crimson	Yes	No	No	No
alizarin	Yes	No	No	No

As nouns, alizarin is a hypernym of alizarin crimson; that is, alizarin is a word with a broader meaning than alizarin crimson:

alizarin crimson: any of various acid dyes; used for dyeing wool scarlet red
alizarin: an orange-red crystalline compound used in making red pigments and in dyeing

Other hypernyms of alizarin crimson include alizarine.

alizarin crimson (noun)	alizarin (noun)
any of various acid dyes; used for dyeing wool scarlet red	an orange-red crystalline compound used in making red pigments and in dyeing