Definition of "tuna" []

• Any of various often large scombroid marine food and game fishes of the genus Thunnus and related genera, many of which, including T. thynnus and the albacore, are commercially important sources of canned fish. Also called tunny. (noun)
• Any of several related fishes, such as the bonito. (noun)
• The edible flesh of tuna, often canned or processed. Also called tuna fish. (noun)
• Any of several flat-jointed tropical American cacti of the genus Opuntia, which includes the prickly pears, especially O. tuna of Jamaica, having yellow flowers and edible red fruit. (noun)
• The edible fruit of any of these cacti. Also called cactus pear. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Chefs like Baggett put the lie to claims by Japanese sushi-industry lobbyists that eating endangered bluefin tuna is essential to Japanese culture."
• "The bluefin tuna is just one living creature suffering from BP's oil."
• "As far as we're aware, all tuna is fish, so we just call it tuna."