Relay

noun
1.
a series of persons relieving one another or taking turns; shift.
2.
a fresh set of dogs or horses posted in readiness for use in a hunt, on a journey, etc.
3.
Sports.

relay race.
a length or leg in a relay race.

4.
Machinery. an automatic control device in which the settings of valves, switches, etc., are regulated by a powered element, as a motor, solenoid, or pneumatic mechanism actuated by a smaller, sensitive element.
5.
Electricity. a device, usually consisting of an electromagnet and an armature, by which a change of current or voltage in one circuit is used to make or break a connection in another circuit or to affect the operation of other devices in the same or another circuit.
6.
(initial capital letter) U.S. Aerospace. one of an early series of experimental low-altitude, active communications satellites.
verb (used with object), relayed, relaying.
7.
to carry forward by or as if by relays:
to relay a message.
8.
to provide with or replace by fresh relays.
9.
Electricity. to retransmit (a signal, message, etc.) by or as if by means of a telegraphic relay.
verb (used without object), relayed, relaying.
10.
Electricity. to retransmit a signal or message electronically.
verb (used with object), relaid, relaying.
1.
re-lay.
verb (used with object), re-laid, re-laying.
1.
to lay again.
noun (ˈriːleɪ)
1.
a person or team of people relieving others, as on a shift
2.
a fresh team of horses, dogs, etc, posted at intervals along a route to relieve others
3.
the act of relaying or process of being relayed
4.

short for relay race
one of the sections of a relay race

5.
an automatic device that controls the setting of a valve, switch, etc, by means of an electric motor, solenoid, or pneumatic mechanism
6.
(electronics) an electrical device in which a small change in current or voltage controls the switching on or off of circuits or other devices
7.
(radio)

a combination of a receiver and transmitter designed to receive radio signals and retransmit them, in order to extend their range
(as modifier): a relay station

verb (transitive) (rɪˈleɪ)
8.
to carry or spread (something, such as news or information) by relays
9.
to supply or replace with relays
10.
to retransmit (a signal) by means of a relay
11.
(Brit) to broadcast (a performance) by sending out signals through a transmitting station: this concert is being relayed from the Albert Hall
relay
(rē’lā)
An electrical switch that is operated by an electromagnet, such as a solenoid. When a small current passes through the electromagnet’s coiled wire, it produces a magnetic field that attracts a movable iron bar, causing it to pivot and open or close the switch.