Nudibranchia vs order Nudibranchia

Nudibranchia and order Nudibranchia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Nudibranchia	Yes	No	No	No
order Nudibranchia	Yes	No	No	No

As nouns, Nudibranchia and order Nudibranchia are synonyms defined as:

Nudibranchia and order Nudibranchia: comprising numerous marine gastropod mollusks lacking a shell in the adult state and usually having a body like a slug

Nudibranchia (noun)	order Nudibranchia (noun)
comprising numerous marine gastropod mollusks lacking a shell in the adult state and usually having a body like a slug	comprising numerous marine gastropod mollusks lacking a shell in the adult state and usually having a body like a slug