- a unit of length equal to one thousandth of a micron; one-billionth of a meter. Symbol: mμ
Origin of millimicron
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- an obsolete name for a nanometre; one millionth of a millimetre
- A unit of length that is equal to one thousandth (10-3) of a micrometer or one billionth (10-9) of a meter; nanometer.