Elec. any of various devices for measuring, comparing, or controlling electric potentials; specif., a kind of resistor that can be varied, as in a rotary device used to control the volume of a radio, TV, etc.
See potentiometer in American Heritage Dictionary 4
(pə-tĕnˌshē-ŏmˈĭ-tər)
noun
An instrument for measuring an unknown voltage by comparison to a standard voltage.
A three-terminal resistor with an adjustable center connection, widely used for volume control in radio and television receivers. Also called pot1.