a pirate flag, usually of black cloth with a white skull and crossbones on it; Jolly Roger.
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.
a signal given to an automobile racing driver to stop, usually because the car may have a dangerous problem that requires inspection.
Origin of black flag
First recorded in 1585–95
Also called blackjack (for defs 1, 2).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for black flag
Knowing that we could not escape from her, the stranger openly showed his colors—the pirate's black-flag.
One hundred black-flag Taaisha, the Khalifa's own Baggara tribesmen and part of his body-guard, charged impetuously.Khartoum Campaign, 1898|Bennet Burleigh
British Dictionary definitions for black flag
another name for the Jolly Roger
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012