| yellow jack | (n) caused by a flavivirus transmitted by a mosquito, Syn. black vomit, yellow fever |
| yellow jack | (n) yellow flag hoist on a ship in quarantine |
| yellow jack | (n) fish of western Atlantic and Gulf of Mexico, Syn. Caranx bartholomaei |
| yellow jacket | (n) small yellow-marked social wasp commonly nesting in the ground, Syn. Vespula maculifrons, yellow hornet |