What is the meaning of the word "quantum jump"?

Definitions:

  1. a sudden large increase or advance copy to clipboard noun
    • After the Internet became cheaper, there was a quantum jump in website development. copy to clipboard
  2. an abrupt transition of an electron, atom, or molecule from one quantum state to another with the emission or absorption of a quantum copy to clipboard noun
    • During the reaction the outermost electron underwent a quantum jump, which was monitored by the physicist. copy to clipboard

Synonyms: