indium vs metallic element

indium and metallic element both are nouns.

Word	Noun	Adjective	Verb	Adverb
indium	Yes	No	No	No
metallic element	Yes	No	No	No

As nouns, metallic element is a hypernym of indium; that is, metallic element is a word with a broader meaning than indium:

indium: a rare soft silvery metallic element; occurs in small quantities in sphalerite
metallic element: any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.

Other hypernyms of indium include metal.

indium (noun)	metallic element (noun)
a rare soft silvery metallic element; occurs in small quantities in sphalerite	any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.