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atomic clock

noun

Simple Definition of atomic clock

  • : a special kind of clock that is extremely exact

Source: Merriam-Webster's Learner's Dictionary

Full Definition of atomic clock

  1. :  a precision clock that depends for its operation on an electrical oscillator regulated by the natural vibration frequencies of an atomic system (as a beam of cesium atoms)

1938

First Known Use of atomic clock

1938


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