niobium vs columbium

niobium and columbium both are nouns.

Word	Noun	Adjective	Verb	Adverb
niobium	Yes	No	No	No
columbium	Yes	No	No	No

As nouns, columbium is a hyponym of niobium; that is, columbium is a word with a more specific, narrower meaning than niobium:

niobium: a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium
columbium: a former name for niobium

niobium (noun)	columbium (noun)
a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium	a former name for niobium