forebrain vs prosencephalon

forebrain and prosencephalon both are nouns.

Word	Noun	Adjective	Verb	Adverb
forebrain	Yes	No	No	No
prosencephalon	Yes	No	No	No

As nouns, forebrain and prosencephalon are synonyms defined as:

forebrain and prosencephalon: the anterior portion of the brain; the part of the brain that develops from the anterior part of the neural tube

forebrain (noun)	prosencephalon (noun)
the anterior portion of the brain; the part of the brain that develops from the anterior part of the neural tube	the anterior portion of the brain; the part of the brain that develops from the anterior part of the neural tube