quarantine flag

noun

, Nautical.

1. a yellow flag, designating the letter Q in the International Code of Signals: flown by itself to signify that a ship has no disease on board and requests a pratique, or flown with another flag to signify that there is disease on board ship.

quarantine flag

noun

1. nautical the yellow signal flag for the letter Q, flown alone from a vessel to indicate that there is no disease aboard and to request pratique or, with a second signal flag, to indicate that there is disease aboard Also calledyellow flagyellow jack

Word History and Origins

Origin of quarantine flag¹

First recorded in 1870–75

Example Sentences

Sick-room and sick-bed are also in common use, and sick-flag is used in place of the American quarantine-flag.

From Project Gutenberg

In that of the midshipmen he may probably find a youth with the quarantine-flag up; that is, in the sick-list.

From Project Gutenberg

The yellow quarantine flag, hoisted to prevent communication; whence the term of the yellow flag, and yellow admirals.

From Project Gutenberg

At her mizzen-peak flew the American ensign, and at the fore-truck the ominous quarantine flag.

From Project Gutenberg

And nobody can see her—Now you hoist the quarantine flag, and I shall pull in the net.

From Project Gutenberg