potash alum vs aluminum

potash alum and aluminum both are nouns.

Word	Noun	Adjective	Verb	Adverb
potash alum	Yes	No	No	No
aluminum	Yes	No	No	No

As nouns, aluminum is a hypernym of potash alum; that is, aluminum is a word with a broader meaning than potash alum:

potash alum: a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum
aluminum: a silvery ductile metallic element found primarily in bauxite

Other hypernyms of potash alum include Al, aluminium, atomic number 13, double salt.

potash alum (noun)	aluminum (noun)
a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum	a silvery ductile metallic element found primarily in bauxite