potentiometer

/P AH0 T EH1 N SH IY0 AA1 M AH0 T ER0/
noun
  1. 1

    A user-adjustable 3 terminal variable resistor that can be used as a voltage divider.

  2. 2

    An instrument that measures a voltage by opposing it with a precise fraction of a known voltage, and without drawing current from the unknown source.

Source: https://en.wiktionary.org/wiki/potentiometer