The millimetre (SI symbol: mm; international spelling) or millimeter (American spelling) is a unit of length in the International System of Units (SI), equal to one thousandth of a metre, the SI base unit of length.
millimetre (mm), unit of length equal to 0.001 metre in the metric system and the equivalent of 0.03937 inch.
MILLIMETRE definition: a unit of length that is equal to 0.001 metres. Learn more.
A millimetre (symbol: mm) is a unit of length in the International System of Units (SI) defined as exactly \frac {1} {1000} 10001 of a metre, or equivalently \frac {1} {10} 101 of a centimetre.
Illustrated definition of Millimeter | Millimetre: A Metric measure of distance used for small lengths. The abbreviation is mm There are 1000 mm in one meter....