Permian period vs Permian

Permian period and Permian both are nouns.

Word	Noun	Adjective	Verb	Adverb
Permian period	Yes	No	No	No
Permian	Yes	No	No	No

As nouns, Permian period and Permian are synonyms defined as:

Permian period and Permian: the period from 280 million to 230 million years ago; distinguished by reptiles

Permian period (noun)	Permian (noun)
the period from 280 million to 230 million years ago; distinguished by reptiles	the period from 280 million to 230 million years ago; distinguished by reptiles