class Hexapoda vs order Lepidoptera

class Hexapoda and order Lepidoptera both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Hexapoda	Yes	No	No	No
order Lepidoptera	Yes	No	No	No

class Hexapoda (noun)	order Lepidoptera (noun)
insects; about five-sixths of all known animal species	moths and butterflies