The Collaborative International Dictionary of English v.0.48:

Quinnat \Quin"nat\, n. [From the native name.] (Zool.)
   The California salmon (Oncorhynchus choicha); -- called
   also chouicha, king salmon, chinnook salmon, and
   Sacramento salmon. It is of great commercial importance.
   [Written also quinnet.]
   [1913 Webster]