Dy vs metallic element

Dy and metallic element both are nouns.

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

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

Dy: a trivalent metallic element of the rare earth group; forms compounds that are highly magnetic
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 Dy include metal.

Dy (noun)	metallic element (noun)
a trivalent metallic element of the rare earth group; forms compounds that are highly magnetic	any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.