glioblastoma vs brain tumor

glioblastoma and brain tumor both are nouns.

Word	Noun	Adjective	Verb	Adverb
glioblastoma	Yes	No	No	No
brain tumor	Yes	No	No	No

As nouns, brain tumor is a hypernym of glioblastoma; that is, brain tumor is a word with a broader meaning than glioblastoma:

glioblastoma: a fast-growing malignant brain tumor composed of spongioblasts; nearly always fatal
brain tumor: a tumor in the brain

Other hypernyms of glioblastoma include brain tumour.

glioblastoma (noun)	brain tumor (noun)
a fast-growing malignant brain tumor composed of spongioblasts; nearly always fatal	a tumor in the brain