class Tardigrada vs tardigrade

class Tardigrada and tardigrade both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Tardigrada	Yes	No	No	No
tardigrade	Yes	No	No	No

class Tardigrada (noun)	tardigrade (noun)
in some classifications considered a separate phylum: microscopic arachnid-like invertebrates living in water or damp moss having 4 pairs of legs and instead of a mouth a pair of stylets or needlelike piercing organs connected with the pharynx	an arthropod of the division Tardigrada