pallium vs neopallium

pallium and neopallium both are nouns.

Word	Noun	Adjective	Verb	Adverb
pallium	Yes	No	No	No
neopallium	Yes	No	No	No

As nouns, neopallium is a hyponym of pallium; that is, neopallium is a word with a more specific, narrower meaning than pallium:

pallium: the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum
neopallium: the cortical part of the neencephalon

Other hyponyms of pallium include neocortex, archipallium, paleocortex.

pallium (noun)	neopallium (noun)
cloak or mantle worn by men in ancient Rome	the cortical part of the neencephalon
(Roman Catholic Church) vestment consisting of a band encircling the shoulders with two lappets hanging in front and back
(zoology) a protective layer of epidermis in mollusks or brachiopods that secretes a substance forming the shell
the layer of unmyelinated neurons (the grey matter) forming the cortex of the cerebrum