Meaning of heavy metal

heav'y met'al

Pronunciation: [key]
  1. any metal with a specific gravity of 5.0 or greater, esp. one that is toxic to organisms, as lead, mercury, copper, and cadmium.
  2. aggressive and heavily amplified rock music, commonly performed by groups that wear spectacular or bizarre costumes.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.