subclass Commelinidae vs class Monocotyledonae

subclass Commelinidae and class Monocotyledonae both are nouns.

Word	Noun	Adjective	Verb	Adverb
subclass Commelinidae	Yes	No	No	No
class Monocotyledonae	Yes	No	No	No

subclass Commelinidae (noun)	class Monocotyledonae (noun)
one of four subclasses or superorders of Monocotyledones; comprises about 19,000 species in 25 families of mostly terrestrial herbs especially of moist places including: Cyperaceae, Gramineae, Bromeliaceae, and Zingiberaceae	comprising seed plants that produce an embryo with a single cotyledon and parallel-veined leaves: includes grasses and lilies and palms and orchids; divided into four subclasses or superorders: Alismatidae, Arecidae, Commelinidae, and Liliidae