ˈmīˌkrän sometimes ˈmi- or _krən noun
( plural microns -nz ; also mi·cra -_krə)
Etymology: New Latin, from Greek mikron, neuter of mikros small — more at micr-
1. : a unit of length equal to one thousandth of a millimeter or about 0.000039 inch — symbol μ
2. : a unit of low pressure (as in a vacuum tube) equal to the pressure of a column of mercury one micron high