a metric unit of length equal to one thousandth of a meter.
noun [集合/集体] 毫米
These sections of rocks are dissected, using a laser, into slices a millimeter or less thick. 采用激光将这些小岩石块切分成一毫米或更薄的薄片。
milli(毫， 千分之一)+metre(米)→毫米
