the act of passing something along from one person or group to another
"the relay was successful"
a crew of workers who relieve another crew
"The exhausted relay arrived just in time to take over and finish the marathon before sunrise."
a fresh team to relieve weary draft animals
"The exhausted horses were replaced by a relay of fresh mules to pull the heavy wagon across the mountain pass."
a race between teams; each member runs or swims part of the distance
"The swimming team won the relay by passing the baton smoothly to each swimmer in turn."
electrical device such that current flowing through it in one circuit can switch on and off a current in a second circuit
"The relay allows a low-voltage control circuit to safely switch on the high-current motor without direct contact."
A new set of hounds.
"The huntmaster ordered a fresh relay of hounds to track the fleeing stag through the dense woods."
control or operate by relay
"The old factory machinery was controlled and operated entirely by a series of electrical relays."
To release a new set of hounds.
"The relay race team ran across the track in perfect synchronization."
Alternative spelling of re-lay
In plain English: To relay something means to pass information from one person to another so it gets shared with someone else.
"The team passed the baton to relay runner during the race."
The word relay comes from the Middle French term relai, which originally referred to a reserve pack of hounds used in hunting. It entered English with this specific meaning before evolving to describe any system where tasks are passed between people or stations.