The Collaborative International Dictionary of English v.0.48:

Sauger \Sau"ger\, n. (Zool.)
   An American fresh-water food fish (Stizostedion Canadense);
   -- called also gray pike, blue pike, hornfish, land
   pike, sand pike, pickering, and pickerel.
   [1913 Webster] Saugh

The Collaborative International Dictionary of English v.0.48:

Pike \Pike\, n. [F. pique; perhaps of Celtic origin; cf. W. pig
   a prick, a point, beak, Arm. pik pick. But cf. also L. picus
   woodpecker (see Pie magpie), and E. spike. Cf. Pick, n. &
   v., Peak, Pique.]
   1. (Mil.) A foot soldier's weapon, consisting of a long
      wooden shaft or staff, with a pointed steel head. It is
      now superseded by the bayonet.
      [1913 Webster]

   2. A pointed head or spike; esp., one in the center of a
      shield or target. --Beau. & Fl.
      [1913 Webster]

   3. A hayfork. [Obs. or Prov. Eng.] --Tusser.
      [1913 Webster]

   4. A pick. [Prov. Eng.] --Wright. Raymond.
      [1913 Webster]

   5. A pointed or peaked hill. [R.]
      [1913 Webster]

   6. A large haycock. [Prov. Eng.] --Halliwell.
      [1913 Webster]

   7. A turnpike; a toll bar. --Dickens.
      [1913 Webster]

   8. (Zool.) sing. & pl. A large fresh-water fish (Esox
      lucius), found in Europe and America, highly valued as a
      food fish; -- called also pickerel, gedd, luce, and
      jack.
      [1913 Webster]

   Note: Blue pike, grass pike, green pike, wall-eyed pike, and
         yellow pike, are names, not of true pike, but of the
         wall-eye. See Wall-eye.
         [1913 Webster]

   Gar pike. See under Gar.

   Pike perch (Zool.), any fresh-water fish of the genus
      Stizostedion (formerly Lucioperca). See Wall-eye,
      and Sauger.

   Pike pole, a long pole with a pike in one end, used in
      directing floating logs.

   Pike whale (Zool.), a finback whale of the North Atlantic
      (Bal[ae]noptera rostrata), having an elongated snout; --
      called also piked whale.

   Sand pike (Zool.), the lizard fish.

   Sea pike (Zool.), the garfish
      (a) .
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pickerel \Pick"er*el\, n. [Dim. of Pike.] [Written also
   pickerell.]
   1. A young or small pike. [Obs.]
      [1913 Webster]

            Bet [better] is, quoth he, a pike than a pickerel.
                                                  --Chaucer.
      [1913 Webster]

   2. (Zool.)
      (a) Any one of several species of freshwater fishes of the
          genus Esox, esp. the smaller species.
      (b) The glasseye, or wall-eyed pike. See Wall-eye.
          [1913 Webster]

   Note: The federation, or chain, pickerel (Esox reticulatus)
         and the brook pickerel (Esox Americanus) are the most
         common American species. They are used for food, and
         are noted for their voracity. About the Great Lakes the
         pike is called pickerel.
         [1913 Webster]

   Pickerel weed (Bot.), a blue-flowered aquatic plant
      (Pontederia cordata) having large arrow-shaped leaves.
      So called because common in slow-moving waters where
      pickerel are often found.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pickerel
    n 1: flesh of young or small pike
    2: any of several North American species of small pike