millimeter
nounA unit of length equal to one thousandth (10−3) of a meter, or 0.0394 inch.
nounThe thousandth part of a meter, equal to 0.03937 inch, or nearly inch. It is denoted by mm.: as, 25.4 mm. is 1 inch.
nounA lineal measure in the metric system, containing the thousandth part of a meter; equal to .03937 of an inch. See 3d
US spelling of
a metric unit of length equal to one thousandth of a meter
