The Collaborative International Dictionary of English v.0.48:

Namaycush \Nam"ay*cush\, n. [Indian name.] (Zool.)
   A large North American lake trout (Salvelinus namaycush).
   It is usually spotted with red, and sometimes weighs over
   forty pounds. Called also Mackinaw trout, lake trout,
   lake salmon, salmon trout, togue, and tuladi.
   [1913 Webster]