A black flag in a car race is the signal for a driver to go to the pits. A black guard is a scoundrel. The ancient Egyptians believed that black cats had divine powers. 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 Learning Network Inc. All rights reserved. Inc. All Rights Reserved.