Electrode (noun)

1. An electrical conductor used to make contact with a nonmetallic part of a circuit.
2. A device for measuring electric potential, consisting of a metal point, wire, or plate that makes contact with a substance and is connected to a measuring instrument.

Origin:

Early 20th century: from electro- + -ode (as in cathode). the term originally denoted a metal point or wire used as an electrical conductor in a vacuum tube.

Examples:

1. The electrode was placed in the solution to measure the concentration of ions.
2. The electrode was connected to a voltmeter to measure the electric potential.
3. The electrode was used to initiate the electrolysis of the water.
4. The electrode was made of gold to prevent contamination of the sample.
5. The electrode was replaced after it became corroded due to prolonged exposure to the harsh environment.