quarantine flag

American  

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.

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quarantine flag British  

noun

1. Also called: yellow flag.   yellow jack.  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

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Etymology

Origin of quarantine flag

First recorded in 1870–75

Example Sentences

They ended up finding a house with an ideal layout for the tank, with a bedroom and bathroom they have since converted into aquarium filtration operations and a separate quarantine tank.

From Seattle Times • Nov. 10, 2021