Source : Webster's Revised Unabridged Dictionary (1913)

Slider \Slid"er\, a.
   See {Slidder}. [Obs.] --Chaucer.

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

   2. (Zo["o]l.) The red-bellied terrapin ({Pseudemys rugosa}).
      [Local, U. S. ]

   {Slider pump}, a form of rotary pump.

Source : WordNet®

slider
     n 1: a person who slips or slides because of loss of traction
          [syn: {skidder}, {slipper}]
     2: someone who races the luge [syn: {luger}]
     3: freshwater turtle of United States and South America;
        frequently raised commercially; some young sold as pets
        [syn: {yellow-bellied terrapin}, {Pseudemys scripta}]
     4: a fastball that curves slightly away from the side from
        which it was thrown