class Arachnida vs order Chelonethida

class Arachnida and order Chelonethida both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Arachnida	Yes	No	No	No
order Chelonethida	Yes	No	No	No

class Arachnida (noun)	order Chelonethida (noun)
a large class of arthropods including spiders and ticks and scorpions and daddy longlegs; have four pairs of walking legs and no wings	false scorpions