Definition

1. Noun:
   • A type of fish: A marine fish (Caranx bartholomaei) found in the western Atlantic Ocean and the Gulf of Mexico, known for its yellowish color.
   • A quarantine flag: A yellow flag (also called the "Q flag") hoisted on a ship to indicate it is under quarantine, requesting pratique (clearance from port health authorities) because it may carry disease.
   • Yellow fever: An acute viral hemorrhagic disease caused by a flavivirus, transmitted by mosquitoes, and characterized by symptoms such as fever and jaundice (which can cause yellowing of the skin).

Usage Examples

• Noun (Fish):
  • The angler was thrilled to catch a large yellow jack.
  • Yellow jack are often found near reefs in the Caribbean.
• Noun (Flag):
  • The ship entered the harbor flying the yellow jack.
  • Seeing the yellow jack, the port authorities knew to approach with caution.
• Noun (Disease):
  • In the 18th century, outbreaks of yellow jack were common in tropical ports.
  • The symptoms of yellow jack include high fever and liver damage.

Advanced Usage

• The term is historically significant, especially in nautical and medical contexts from the 18th and 19th centuries.
• As a flag, the yellow jack specifically signals a request for quarantine inspection, not necessarily that disease is confirmed on board.

Variants and Related Words

• Yellow flag: The more common term for the quarantine flag.
• Yellow fever: The standard medical term for the disease.
• Quarantine flag: A synonym for the yellow flag.
• Jack: In nautical contexts, a flag flown on a ship's jackstaff.

Synonyms

• For the fish: amberjack (a related species, but not identical).
• For the flag: quarantine flag, Q flag.
• For the disease: yellow fever, black vomit (an archaic term based on a symptom).

Related Phrases

• To fly the yellow jack: To display the quarantine flag.
  • The vessel had to fly the yellow jack for 40 days before being granted pratique.
• Struck by yellow jack: Infected with yellow fever.
  • Many sailors were struck by yellow jack during the voyage.

Noun

1. fish of western Atlantic and Gulf of Mexico
2. yellow flag hoist on a ship in quarantine
3. caused by a flavivirus transmitted by a mosquito