The Collaborative International Dictionary of English v.0.48:

Torsk \Torsk\, n. [Dan.; akin to Icel. [thorn]orskr a codfish,
   G. dorsch.] (Zool.)
   (a) The cusk. See Cusk.
   (b) The codfish. Called also tusk.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tusk \Tusk\ (t[u^]sk), n. (Zool.)
   Same as Torsk.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tusk \Tusk\, n. [OE. tusk, the same word as tusch, AS. tusc. See
   Tush a tooth.]
   1. (Zool.) One of the elongated incisor or canine teeth of
      the wild boar, elephant, etc.; hence, any long, protruding
      tooth.
      [1913 Webster]

   2. (Zool.) A toothshell, or Dentalium; -- called also
      tusk-shell.
      [1913 Webster]

   3. (Carp.) A projecting member like a tenon, and serving the
      same or a similar purpose, but composed of several steps,
      or offsets. Thus, in the illustration, a is the tusk, and
      each of the several parts, or offsets, is called a tooth.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tusk \Tusk\ (t[u^]sk), v. i.
   To bare or gnash the teeth. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cusk \Cusk\ (k[u^]sk), n. (Zool.)
   A large, edible, marine fish (Brosmius brosme), allied to
   the cod, common on the northern coasts of Europe and America;
   -- called also tusk and torsk.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tusk
    n 1: a hard smooth ivory colored dentine that makes up most of
         the tusks of elephants and walruses [syn: ivory, tusk]
    2: a long pointed tooth specialized for fighting or digging;
       especially in an elephant or walrus or hog
    v 1: stab or pierce with a horn or tusk; "the rhino horned the
         explorer" [syn: horn, tusk]
    2: remove the tusks of animals; "tusk an elephant" [syn: tusk,
       detusk]