What is the meaning of Black_metal?

Iron, or similar metals worked by a blacksmith

A subgenre of heavy metal music employing fast tempos, shrieked vocals, highly distorted guitars, double-kick drumming, raw recording and unconventional song structure, often emphasizing antireligious and misanthropic themes.

Any form of extreme metal having a Satanic or anti-Christian theme.

black metal (extreme-metal genre)

black metal

black metal (a subgenre of heavy metal)

black metal

Source: wiktionary.org