1. noun /ˈriːleɪ/
a) An electrical actuator that allows a relatively small electrical voltage or current to control a larger voltage or current.
b) A track and field discipline where runners take turns in carrying a baton from start to finish. Most common events are 4x100 meter and 4x400 meter competitions.
2. verb /ˈriːleɪ/
a) To pass or transfer from one person to another, especially repeatedly through a series of persons.
He had to relay the tiles because the cement was too dry.
b) To lay again.
Wikipedia foundation.