relay
UK: ˈriːleɪ | US: ˈriːleɪ
n. 1. A race in which team members take turns to complete parts of the course.
n. 2. A device that activates or controls another device in response to a signal.
vt. 3. To pass along or transmit (information, a message, etc.).
The word "relay" originates from Old French relai ("hounds left behind to resume a chase"), derived from relaier ("to leave behind"). It combines re- (indicating repetition) and laier (an archaic form of "to leave" or "to lay"). The modern sense evolved from the idea of passing something (e.g., hounds, messages, or tasks) in stages. The technical use for electrical devices (19th century) metaphorically extends this concept of transmission.
She ran the final leg of the relay race.
The satellite acts as a relay for communication signals.
Please relay the instructions to the team.
The relay switch automatically turns on the lights.
News of the victory was relayed across the country.