Source : Webster's Revised Unabridged Dictionary (1913)

Tuna \Tu"na\, n. (Bot.)
   The {Opuntia Tuna}. See {Prickly pear}, under {Prickly}.

Tuna \Tu"na\, n. [Cf. {Tunny}.] (Zo["o]l.)
   (a) The tunny.
   (b) The bonito, 2.

Source : WordNet®

tuna
     n 1: tropical American flat-jointed prickly pear; Jamaica [syn: {Opuntia
          tuna}]
     2: important warm-water fatty fish of the genus Thunnus of the
        family Scombridae; usually served as steaks [syn: {tuna
        fish}, {tunny}]
     3: any very large marine food and game fish of the genus
        Thunnus; related to mackerel; chiefly of warm waters [syn:
         {tunny}]
     4: New Zealand eel [syn: {Anguilla sucklandii}]