verb
1 rare To remove the keystone from (an arch, etc.). Also in extended use. Compare "key".
2 rare To unfasten by removing a pin, wedge, bolt, etc. Compare "key".
3To set (a transmitter, microphone, etc.) to stop transmitting.
Origin
Late 17th century; earliest use found in 13th Volume Wren Society. From un- + key.
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