Definition: [noun] a group of people or animals engaged in a task or activity for a period of time and then replaced by a similar group.
Example: the wagons were pulled by relays of horses
Definition: [noun] an electrical device, typically incorporating an electromagnet, which is activated by a current or signal in one circuit to open or close another circuit.
Definition: [noun] a device to receive, reinforce, and retransmit a radio or television signal.
Example: TV transmitters and relay stations
Definition: [verb] receive and pass on (information or a message).
Example: she intended to relay everything she had learned