agapanthus vs liliaceous plant

agapanthus and liliaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
agapanthus	Yes	No	No	No
liliaceous plant	Yes	No	No	No

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

agapanthus: any of various plants of the genus Agapanthus having umbels of showy blue to purple flowers
liliaceous plant: plant growing from a bulb or corm or rhizome or tuber

agapanthus (noun)	liliaceous plant (noun)
any of various plants of the genus Agapanthus having umbels of showy blue to purple flowers	plant growing from a bulb or corm or rhizome or tuber