noun

millimeter

A metric unit of length equal to one thousandth of a meter.

Each small mark on this ruler represents one millimeter.

Etymology

The metric prefix milli- specifies one thousandth of the named unit. Attached to meter, it creates the name for one thousandth of a meter.

More examples

  • The glass is four millimeters thick.
  • The forecast calls for ten millimeters of rain.
  • Move the shelf a few millimeters to the left.

Forms

millimeter · millimeters

Similar words

centimeter
A metric length unit equal to ten millimeters.
meter
A metric length unit equal to one thousand millimeters.