class Arachnida vs Arachnida

class Arachnida and Arachnida both are nouns.

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

As nouns, class Arachnida and Arachnida are synonyms defined as:

class Arachnida and Arachnida: a large class of arthropods including spiders and ticks and scorpions and daddy longlegs; have four pairs of walking legs and no wings

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