slipstick

slipstick
    n 1: analog computer consisting of a handheld instrument used
         for rapid calculations; have been replaced by pocket
         calculators [syn: {slide rule}, {slipstick}]
    

Slide rule \Slide" rule`\, n.
   a thin, flat calculating device consisting of a fixed outer
   piece and a movable middle piece. Both pieces are graduated
   in such a way (as, by a logarithmic scale) that
   multiplication, division, and other mathematical functions of
   an input variable may be rapidly determined by movement of
   the middle pieces to a location on one scale corresponding to
   the input value, and reading off the result on another scale.
   A movable window with a hairline assists in alignment of the
   scales. This device has been largely superseded by the
   electronic calculator, which has a greater precision than the
   slide rule. Also called colloquially {slipstick}.
   [PJC]