Db vs chemical element

Db and chemical element both are nouns.

Word	Noun	Adjective	Verb	Adverb
Db	Yes	No	No	No
chemical element	Yes	No	No	No

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

Db: a transuranic element with atomic number 105
chemical element: any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter

Other hypernyms of Db include element.

Db (noun)	chemical element (noun)
a transuranic element with atomic number 105	any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter