mi·crom·e·ter
noun- (US English) (British English micrometre)(symbol μm)a unit for measuring length, equal to one millionth of a metre
微米（相当于百万分之一米） - /maɪˈkrɒmɪtə(r)//maɪˈkrɑːmɪtər/a device used for measuring very small distances or spaces
螺旋测微器；千分尺