1) earth electrode
2) ground electrode
a conductor or group of conductors in intimate contact with and providing an electrical connection to earth
GRM: n. (1,2)
REG: British English (1), American English (2)
References:
SPE earth rod
SPE earth plate
SPE ground rod
SPE ground plate
SPE remote earth
SPE separate ground electrodes
SPE separate earth electrodes
SPE ground strip
SPE remote ground
SPE earth strip

ENERGY TERM COURTESY OF ENERGY.EU