- yellow fever
- a yellow flag used as a signal of quarantine
- an edible, gold-and-silver marine jack fish (Caranx bartholomaei) found near Florida and the West Indies
See yellow jack in American Heritage Dictionary 4
- A yellowish-silver carangid food fish (Caranx bartholomaei) of western Atlantic and Caribbean waters.
- Nautical A yellow flag hoisted on a ship to request pratique or warn of disease on board.
- See yellow fever.