millimicron millimeter • millimolar · · · Info · Definitions · Synonyms · Characters · · millimicron · · Text Latin · · Script 11 · · Length Definitions · · · (noun) a metric unit of length equal to one billionth of a meter. Synonyms: nanometer, nanometre, nm, micromillimeter, micromillimetre. · · Noun Definition 1 Synonyms · · · nanometer · · Synonym 1 nanometre · · Synonym 2 nm · · Synonym 3 micromillimeter · · Synonym 4 micromillimetre · · Synonym 5 Characters · · c latin small letter c U+0063 i latin small letter i U+0069 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072