relay
n//ɹiˈleɪ//stafett, relä
(athletics) A track and field discipline where runners take turns in carrying a baton from start to finish. The most common events are 4×100 meter and 4×400 meter competitions. [from 19th c.]
(electronics) An electrical actuator that allows a relatively small electrical voltage or current to control a larger voltage or current. [from 19th c.]