[count] 1 : a race between teams in which each team member runs, swims, etc., a different part of the race
▪ I'm running (in) the relay at tomorrow's track meet. ▪ the 4x100 relay [=a relay with four parts that are 100 meters each] ▪ Our relay team is training for next weekend's race. 2 : the act of passing something from one person or device to another
▪ a satellite relay of a television signal ▪ (baseball) The shortstop's relay (throw) from center field was too late to catch the runner at home. ; also : a system for doing this
▪ We set up a relay to carry buckets of water to the campsite. ▪ a satellite relay system 3 : a group of people, horses, etc., that takes the place of others so that something (such as a job or an activity) is done continuously
▪ They worked in relays to clear the rubble. 4 technical : a device that is used to cause a switch to open or close automatically when there is a change in the current that is flowing through a circuit
▪ an electromagnetic relay