brainpan vs braincase

brainpan and braincase both are nouns.

Word	Noun	Adjective	Verb	Adverb
brainpan	Yes	No	No	No
braincase	Yes	No	No	No

As nouns, brainpan and braincase are synonyms defined as:

Other synonyms of brainpan include cranium.

brainpan (noun)	braincase (noun)
the part of the skull that encloses the brain	the part of the skull that encloses the brain