class Dicotyledonae vs order Plantaginales

class Dicotyledonae and order Plantaginales both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Dicotyledonae	Yes	No	No	No
order Plantaginales	Yes	No	No	No

class Dicotyledonae (noun)	order Plantaginales (noun)
comprising seed plants that produce an embryo with paired cotyledons and net-veined leaves; divided into six (not always well distinguished) subclasses (or superorders): Magnoliidae and Hamamelidae (considered primitive), Caryophyllidae (an early and distinctive offshoot), and three more or less advanced groups: Dilleniidae, Rosidae, Asteridae	coextensive with the family Plantaginaceae