black flag

noun

1. a pirate flag, usually of black cloth with a white skull and crossbones on it; Jolly Roger.
2. a flag having two yellow and two black squares, signifying the letter L in the International Code of Signals: formerly so called when used by itself to indicate the presence of cholera on board a vessel.
3. a signal given to an automobile racing driver to stop, usually because the car may have a dangerous problem that requires inspection.

black flag

noun

1. another name for the Jolly Roger

Word History and Origins

Origin of black flag¹

First recorded in 1585–95

Example Sentences

The sky was a black flag at first light.

From Los Angeles Times

The FBI has said the black flag of the Islamic State group was found inside the vehicle which ploughed into partygoers, along with two suspected improvised explosive devices discovered nearby.

From BBC

The green and black flag of the opposition, now ubiquitous, stands out.

From BBC

Chapman scrambled to the officials’ stand, pleading with Chief Steward Harlan Fengler to put out a black flag for Jones, calling him to the pits.

From Los Angeles Times

The couple have hung a large black flag from their veranda, in solidarity with the hostages - 19 of them from Kfar Aza.

From BBC