Rheostat (noun)

A resistor used for controlling the flow of electric current by adjusting the resistance in a circuit.

Origin:

Derived from greek words 'rhein' meaning 'to flow' and 'statis' meaning 'stationary'. first used in english in 1884.

Examples:

1. A rheostat can be used to control the brightness of a lamp.
2. The amplifier was equipped with a rheostat that regulated the volume.
3. The rheostat was adjusted to lower the temperature in the room.
4. He checked the rheostat to see if it was functioning properly.
5. The rheostat was set to a high resistance to reduce the flow of electric current.