[1] : The Collaborative International Dictionary of English v.0.48

millimicron \mil"limi`cron\, n. milli- + micron.
   the thousandth part of a micron or the millionth part of a
   millimeter; one nanometer; -- a unit of length sometimes used
   in measuring light waves, etc.
   webster 1913 suppl.

[2] : WordNet (r) 2.0

millimicron
     n : a metric unit of length equal to one billionth of a meter
         syn: nanometer, nanometre, nm, micromillimeter,
         micromillimetre
see also:
nanometer nanometre nm micromillimeter micromillimetre 

Millimicron >> M Words
Millimicron, definition of term: Millimicron
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