noun, plural mil·li·mi·crons, mil·li·mi·cra [mil-uh-mahy-kruh] /ˈmɪl əˌmaɪ krə/.

a unit of length equal to one thousandth of a micron; one-billionth of a meter. Symbol: mμ

Compare nanometer.

Origin of millimicron

First recorded in 1900–05; milli- + micron Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for millimicron



an obsolete name for a nanometre; one millionth of a millimetre
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

millimicron in Medicine




A unit of length that is equal to one thousandth (10-3) of a micrometer or one billionth (10-9) of a meter; nanometer.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.