The Collaborative International Dictionary of English v.0.48:

Slider \Slid"er\, n.
   1. One who, or that which, slides; especially, a sliding part
      of an instrument or machine.
      [1913 Webster]

   2. (Zool.) The red-bellied terrapin (Pseudemys rugosa).
      [Local, U. S. ]
      [1913 Webster]

   3. (Zool.) any of several North American freshwater turtles
      of the genus Chrysemis; some, such as Chrysemis
      scripta are sold commercially as pets. --[RHUD]
      [PJC]

   4. (Baseball) a fast pitch that breaks slightly just in front
      of the batter, in the same direction as a curve ball (i.
      e., away from the side from which it was thrown).
      [PJC]

   Slider pump, a form of rotary pump.
      [1913 Webster]