quarantine flag

A ship flies a quarantine flag as it enters the harbor.

Definition

1. Noun:
   • A yellow flag: "quarantine flag" refers to a yellow flag (historically the "Yellow Jack") flown by a ship to indicate that it is in quarantine, typically because of infectious disease on board, or to request pratique (clearance) from health authorities.

Usage Examples

• Noun:
  • The ship raised the quarantine flag as it entered the harbor, signaling that the crew was suffering from cholera. (The yellow flag was hoisted to show the vessel needed medical inspection.)
  • During the pandemic, vessels were required to display a quarantine flag for 14 days before docking. (The flag indicated a period of isolation for health reasons.)

Advanced Usage

• "to fly the quarantine flag": to display the yellow flag as a formal signal of disease or isolation.
  • The captain ordered the crew to fly the quarantine flag after several sailors developed fevers. (The flag was raised to alert port authorities.)

Variants and Related Words

• Quarantine (n): a state, period, or place of isolation to prevent the spread of disease.

  • The passengers were placed in quarantine for two weeks. (They were isolated from others.)

• Flag (n): a piece of cloth with a distinctive design, used as a symbol or signal.

  • The flag was yellow with black markings. (The specific design of the quarantine flag.)

Synonyms

• Yellow flag: the common term for the quarantine flag.
• Yellow Jack: an older, historical name for the quarantine flag, especially in maritime contexts.

Related Idioms

• "to show the yellow flag": to indicate illness or danger, often metaphorically.
  • The company showed the yellow flag by announcing layoffs. (They signaled trouble ahead, similar to a quarantine flag's warning.)