order Hemiptera vs class Hexapoda

order Hemiptera and class Hexapoda both are nouns.

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

order Hemiptera (noun)	class Hexapoda (noun)
plant bugs, bedbugs, some true bugs; also includes suborders Heteroptera (true bugs) and Homoptera (e.g., aphids, plant lice and cicadas)	insects; about five-sixths of all known animal species