decumary vs hydrangea

decumary and hydrangea both are nouns.

Word	Noun	Adjective	Verb	Adverb
decumary	Yes	No	No	No
hydrangea	Yes	No	No	No

As nouns, hydrangea is a hypernym of decumary; that is, hydrangea is a word with a broader meaning than decumary:

decumary: woody climber of southeastern United States having white flowers in compound terminal clusters
hydrangea: any of various deciduous or evergreen shrubs of the genus Hydrangea

decumary (noun)	hydrangea (noun)
woody climber of southeastern United States having white flowers in compound terminal clusters	any of various deciduous or evergreen shrubs of the genus Hydrangea