Source : Webster's Revised Unabridged Dictionary (1913)

Potentiometer \Po*ten`ti*om"e*ter\, n. [Potential + -meter.]
   (Elec.)
   An instrument for measuring or comparing electrial potentials
   or electro-motive forces.

Source : WordNet®

potentiometer
     n 1: a measuring instrument for measuring direct current
          electromotive forces
     2: a resistor with three terminals, the third being an
        adjustable center terminal; used to adjust voltages in
        radios and TV sets [syn: {pot}]