In China, black is for little boys. Black is associated with sophistication and elegance. A black belt in karate identifies an expert. A black flag in a car race is the signal for a driver to go to the pits. A black guard is a scoundrel.
Black lung is a coal miner's disease caused by the frequent inhaling of coal dust.
Black mail is getting things by threat. Black market is illegal trade in goods or money. A black sheep is an outcast. A black out is a period of darkness from the loss of electricity, for protection against nighttime air raids, or, in the theater, to separate scenes in a play. The ancient Egyptians believed that black cats had divine powers.