brainstem vs encephalon

brainstem and encephalon both are nouns.

Word	Noun	Adjective	Verb	Adverb
brainstem	Yes	No	No	No
encephalon	Yes	No	No	No

brainstem (noun)	encephalon (noun)
the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus	that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord