(Of a mechanism) maintained at a constant rate of rotation by means of a vibrating quartz crystal; (of speed control) that maintains a constant rate by this means.
Origin
1970s; earliest use found in Time.
Definition of quartz-locked in US English:
quartz-locked
adjective
Mineralogy
(Of a mechanism) maintained at a constant rate of rotation by means of a vibrating quartz crystal; (of speed control) that maintains a constant rate by this means.