heavy metal is a noun meaning "a metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight (especially one that is poisonous like mercury or lead)". It carries 2 recorded senses.
a metal of relatively high density (specific gravity greater than about 5) or of high relative atomic weight (especially one that is poisonous like mercury or lead)
loud and harsh sounding rock music with a strong beat; lyrics usually involve violent or fantastic imagery
Definitions, synonyms and semantic relations for heavy metal come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.