rhombencephalon vs encephalon

rhombencephalon and encephalon both are nouns.

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

rhombencephalon (noun)	encephalon (noun)
the posterior portion of the brain including cerebellum and brainstem	that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord