Source : Webster's Revised Unabridged Dictionary (1913)

Integrator \In"te*gra`tor\, n. (Math. & Mech.)
   That which integrates; esp., an instrument by means of which
   the area of a figure can be measured directly, or its moment
   of inertia, or statical moment, etc., be determined.

Source : WordNet®

integrator
     n : a measuring instrument for measuring the area of an
         irregular plane figure [syn: {planimeter}]