heavy metal  
noun uk/ˌhev.i ˈmet.əl/ us/ˌhev.i ˈmet̬.əl/
  (METAL)     
  [ C ] chemistry specialized重金属(密度大且通常有毒的金属) 
a dense (= heavy in relation to its size) and usually poisonous metal, such as lead
   (MUSIC)     
 [ U ]重金属摇滚乐 
a style of rock music with a strong beat, played very loudly using electric guitars