macroscopicity

/M AE1 K R AH0 S K AA1 P IH1 S AH0 T IY0/
noun
  1. 1

    (uncountable) The quality or state of being macroscopic.

  2. 2

    (countable, quantum mechanics) A formal measure of the size of a quantum mechanical system or experiment which, while typically larger than the atomic scale, has not undergone decoherence.