1. Largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics
   "A single bluefin tuna can sell for thousands of dollars at auction";
   - bluefin tuna, horse mackerel, Thunnus thynnus
    
2. Flesh of very large tuna
   "The high-end restaurant served seared bluefin tuna steak as its signature dish";
   - bluefin tuna

Derived forms: bluefins

Type of: tuna, tuna fish, tunny

Part of: genus Thunnus, Thunnus

Encyclopedia: Bluefin