class Arachnida vs order Araneida

class Arachnida and order Araneida both are nouns.

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

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