neoencephalon vs neencephalon

neoencephalon and neencephalon both are nouns.

Word	Noun	Adjective	Verb	Adverb
neoencephalon	Yes	No	No	No
neencephalon	Yes	No	No	No

As nouns, neoencephalon and neencephalon are synonyms defined as:

neoencephalon and neencephalon: the part of the brain having the most recent phylogenetic origin; the cerebral cortex and related parts

neoencephalon (noun)	neencephalon (noun)
the part of the brain having the most recent phylogenetic origin; the cerebral cortex and related parts	the part of the brain having the most recent phylogenetic origin; the cerebral cortex and related parts