D defs.my
Entry 1 sense Webster, 1913

micron

/mīk'-ränˌ/ · mic·ron · IPA /ˈmaɪkɹɒn/
01 n. A measure of length; the thousandth part of one millimeter; the millionth part of a meter.
  1. 1.
    A measure of length; the thousandth part of one millimeter; the millionth part of a meter.(Physics)