dracaena vs century plant

dracaena and century plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
dracaena	Yes	No	No	No
century plant	Yes	No	No	No

As nouns, century plant is a hypernym of dracaena; that is, century plant is a word with a broader meaning than dracaena:

dracaena: an agave that is often cultivated for its decorative foliage
century plant: tropical American plants with basal rosettes of fibrous sword-shaped leaves and flowers in tall spikes; some cultivated for ornament or for fiber

Other hypernyms of dracaena include agave, American aloe.

dracaena (noun)	century plant (noun)
an agave that is often cultivated for its decorative foliage	tropical American plants with basal rosettes of fibrous sword-shaped leaves and flowers in tall spikes; some cultivated for ornament or for fiber