A tuna is a large saltwater fish. The weight of a tuna varies enormously, from four pounds to more than 1,500 pounds!

It's common to refer to the kind of tuna that's sold as food in cans as "tuna fish." If you're mainly familiar with the tuna on your tuna fish sandwich, you might be surprised to learn that the Atlantic bluefin tuna lives to be about 50 years old, and can measure almost seven feet long. The word tuna comes from the Arabic root tun via the Spanish atún.

Definitions of tuna
  1. noun
    important warm-water fatty fish of the genus Thunnus of the family Scombridae; usually served as steaks
    synonyms: tuna fish, tunny
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    relatively small tuna with choice white flesh; major source of canned tuna
    flesh of mostly Pacific food fishes of the genus Sarda of the family Scombridae; related to but smaller than tuna
    bluefin, bluefin tuna
    flesh of very large tuna
    type of:
    saltwater fish
    flesh of fish from the sea used as food
  2. noun
    any very large marine food and game fish of the genus Thunnus; related to mackerel; chiefly of warm waters
    synonyms: tunny
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    Thunnus alalunga, albacore, long-fin tunny
    large pelagic tuna the source of most canned tuna; reaches 93 pounds and has long pectoral fins; found worldwide in tropical and temperate waters
    Thunnus thynnus, bluefin, bluefin tuna, horse mackerel
    largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics
    Thunnus albacares, yellowfin, yellowfin tuna
    may reach 400 pounds; worldwide in tropics
    type of:
    food fish
    any fish used for food by human beings
    scombroid, scombroid fish
    important marine food and game fishes found in all tropical and temperate seas; some are at least partially endothermic and can thrive in colder waters
  3. noun
    New Zealand eel
    synonyms: Anguilla sucklandii
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    type of:
    voracious snakelike marine or freshwater fishes with smooth slimy usually scaleless skin and having a continuous vertical fin but no ventral fins
  4. noun
    tropical American prickly pear of Jamaica
    synonyms: Opuntia tuna
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    type of:
    prickly pear, prickly pear cactus
    cacti having spiny flat joints and oval fruit that is edible in some species; often used as food for stock
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