The Collaborative International Dictionary of English v.0.48:

Katsuwonidae \Katsuwonidae\ prop. n.
   A natural family of fish which in some classifications is
   considered a separate family comprising the oceanic bonitos.

   Syn: family Kasuwonidae.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Katsuwonidae
    n 1: in some classifications considered a separate family
         comprising the oceanic bonitos [syn: Katsuwonidae,
         family Kasuwonidae]