blue peterblue peter
a blue signal flag with a white square in the center, flown by a merchant ship to show it is ready to sail
Origin of blue peterprobably ; from blue repeater, signal flag used in British Navy
A blue flag with a white square in the center, flown to signal that a ship is ready to sail.
Origin of blue peterFrom the fact that it represents the letter P in the International Code of Symbols.