The Collaborative International Dictionary of English v.0.48:

Bender \Bend"er\, n.
   1. One who, or that which, bends.
      [1913 Webster]

   2. An instrument used for bending.
      [1913 Webster]

   3. A drunken spree. [Low, U. S.] --Bartlett.
      [1913 Webster]

   4. A sixpence. [Slang, Eng.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

bender
    n 1: a tool for bending; "he used pliers as a bender"
    2: revelry in drinking; a merry drinking party [syn: carouse,
       carousal, bender, toot, booze-up]
    3: a pitch of a baseball that is thrown with spin so that its
       path curves as it approaches the batter [syn: curve, curve
       ball, breaking ball, bender]