[mi.crom.e.ter] n [F micrometre, fr. micr- + -metre -meter] (1670) 1: an instrument used with a telescope or microscope for measuring minute distances
2: a caliper for making precise measurements that has a spindle moved by a finely threaded screw
[2]mi.cro.me.ter n [ISV micr- + [3]meter] (1880): a unit of length equal to one millionth of a meter--called also micron--see metric system table